Internet Info 1994 March

home *** CD-ROM | disk | FTP | other *** search

/ Internet Info 1994 March / Internet Info CD-ROM (Walnut Creek) (March 1994).iso / standards / scsi / scsi1_docs_7.6 < prev next >

Wrap

Internet Message Format | 1993-07-15 | 82.7 KB

From coffin@ROCKY2.ROCKEFELLER.EDU Thu Mar 22 08:44:30 1990 Flags: 000000000000 Return-Path: <coffin@ROCKY2.ROCKEFELLER.EDU> Received: from ROCKY2.ROCKEFELLER.EDU by rascal.ics.utexas.edu. (4.0/SMI-4.0) id AA28538; Thu, 22 Mar 90 08:44:16 CST Received: by ROCKY2.ROCKEFELLER.EDU (5.61/1.34) id AA15152; Thu, 22 Mar 90 09:42:14 -0500 Message-Id: <9003221442.AA15152@ROCKY2.ROCKEFELLER.EDU> To: werner@rascal.ics.utexas.edu Subject: scsiDocs Part6 of 7 Date: Thu, 22 Mar 90 09:41:34 -0500 From: coffin@ROCKY2.ROCKEFELLER.EDU .fo Section 10 # 10. Group 0 Command Descriptions for Printer Devices The Group 0 commands for printer devices shall be as shown in Table 10-1. Table 10-1 Group 0 Commands for Printer Devices ============================================================================== Operation Code Type Command Name Section ------------------------------------------------------------------------------ 00H O TEST UNIT READY 7.1.1 01H V 02H V 03H M REQUEST SENSE 7.1.2 04H O FORMAT 10.1 05H V 06H V 07H V 08H V 09H V 0AH M PRINT 10.2 0BH O SLEW AND PRINT 10.3 0CH V 0DH V 0EH V 0FH V 10H O FLUSH BUFFER 10.4 11H V 12H E INQUIRY 7.1.3 13H V 14H O RECOVER BUFFERED DATA 10.5 15H O MODE SELECT 10.6 16H O RESERVE UNIT 10.7.1 17H O RELEASE UNIT 10.7.2 18H O COPY 7.1.4 19H V 1AH O MODE SENSE 10.8 1BH O STOP PRINT 10.9 1CH O RECEIVE DIAGNOSTIC RESULTS 7.1.5 1DH O SEND DIAGNOSTIC 7.1.6 1EH R 1FH R ============================================================================== Key: M = Command implementation is mandatory. E = Command implementation is required for SCSI devices that support device-independent self-configuring software. O = Command implementation is optional. R = Operation code is reserved for future standardization. V = Operation code is available for vendor unique commands. .pa 10.1 FORMAT Command Peripheral Device Type: Printer Operation Code Type: Optional Operation Code: 04H Table 10-2 FORMAT Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | Format Type | -----|-----------------------------------------------------------------------| 2 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Transfer Length | -----|-----------------------------------------------------------------------| 4 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The FORMAT command (Table 10-2) provides a means for the initiator to specify forms or fonts to printers that support programmable forms or fonts. The format information sent is vendor unique since it is peripheral-device specific. The format type field specifies the type of format information to be transferred from the initiator to the target. This field is defined as follows: DB(1) DB(0) Format Type ----- ----- ------------- 0 0 Set Form 0 1 Set Font 1 0 Vendor Unique 1 1 Reserved The transfer length specifies the length in bytes of format information that shall be sent during the DATA OUT phase. A transfer length of zero indicates that no format information shall be sent. This condition shall not be considered as an error. .pa 10.2 PRINT Command Peripheral Device Type: Printer Operation Code Type: Mandatory Operation Code: 0AH Table 10-3 PRINT Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Transfer Length | -----|-----------------------------------------------------------------------| 4 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The PRINT command (Table 10-3) transfers the specified number of bytes from the initiator to the target to be printed. The data sent is application dependent. The transfer length specifies the length in bytes of data that shall be sent during the DATA OUT phase. A transfer length of zero indicates that no data shall be sent. This condition shall not be considered as an error. .pa 10.3 SLEW AND PRINT Command Peripheral Device Type: Printer Operation Code Type: Optional Operation Code: 0BH Table 10-4 SLEW AND PRINT Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | Channel| -----|-----------------------------------------------------------------------| 2 | Slew Value | -----|-----------------------------------------------------------------------| 3 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 4 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The SLEW AND PRINT command (Table 10-4) transfers the specified number of bytes from the initiator to the target to be printed. The data sent is application dependent. This command is provided for printers that do not support forms control information imbedded within the print data. The transfer length specifies the length in bytes of data that shall be sent during the DATA OUT phase. A transfer length of zero indicates that no data shall be sent. This condition shall not be considered as an error. If the channel bit is zero, the slew value specifies the number of lines the form shall be advanced before printing. A value of 255 indicates that the form shall be advanced to the first line of the next form before printing. If the channel bit is one, the slew value specifies the forms control channel number to which the form shall be advanced prior to printing the data. If the channel bit is one, and the channel option is not implemented, the command shall be terminated with a CHECK CONDITION status and the sense key shall be set to ILLEGAL REQUEST. .pa 10.4 FLUSH BUFFER Command Peripheral Device Type: Printer Operation Code Type: Optional Operation Code: 10H Table 10-5 FLUSH BUFFER Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The FLUSH BUFFER command (Table 10-5) provides a means for an initiator to ensure that the data have been successfully printed prior to releasing the peripheral device. This is useful for applications that wish to handle any error or exception conditions (e.g., end-of-medium) prior to termination of the application. When all buffered data are actually printed the command shall be terminated with a GOOD status. If it is not possible to finish printing all of the buffered data (due to an error or exception condition on the peripheral device), then this command shall be terminated with a CHECK CONDITION status and the appropriate sense key. .pa 10.5 RECOVER BUFFERED DATA Command Peripheral Device Type: Printer Operation Code Type: Optional Operation Code: 14H Table 10-6 RECOVER BUFFERED DATA Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Transfer Length | -----|-----------------------------------------------------------------------| 4 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The RECOVER BUFFERED DATA command (Table 10-6) returns to the initiator the data that has been sent to the target, but not yet printed. This command is normally used only to recover from error or exception conditions that make it impossible to print the buffered data. The order in which the data is transferred from the target to the initiator is the same as it was when the data was previously transferred using the PRINT command or SLEW AND PRINT command. Data that is transferred by this command is deleted >From the target data buffer. One or more RECOVER BUFFERED DATA commands may be used to return the unprinted buffered data. If an attempt is made to recover more data than is contained in the buffer, the command shall be terminated with a CHECK CONDITION status and the sense key shall be set to NO SENSE. In addition, the EOM, the valid, and the ILI bits in extended sense shall be set to one. The information bytes shall be set to the difference (residue) between the transfer length and the actual number of bytes returned. The transfer length specifies the maximum length in bytes of data that shall be transferred during the DATA IN phase. A transfer length of zero indicates that no data shall be transferred. This condition shall not be considered as an error. .pa 10.6 MODE SELECT Command Peripheral Device Type: Printer Operation Code Type: Optional Operation Code: 15H Table 10-7 MODE SELECT Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Parameter List Length | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The MODE SELECT command (Table 10-7) provides a means for the initiator to specify medium, logical unit, or peripheral device parameters to the target. The parameter list length specifies the length in bytes of the MODE SELECT parameter list that shall be transferred during the DATA OUT phase. A parameter list length of zero indicates that no data shall be transferred. This condition shall not be considered as an error. The MODE SELECT parameter list (Table 10-8) contains a four-byte header, followed by the vendor unique parameters, if any. Table 10-8 MODE SELECT Parameter List ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Reserved | -----|-----------------------------------------------------------------------| 1 | Reserved | -----|-----------------------------------------------------------------------| 2 |Reserved| Buffered Mode | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | ============================================================================== | Vendor Unique Parameter(s) | ============================================================================== 0 _ n| Vendor Unique | | Parameter Byte(s) | ============================================================================== A buffered mode of zero indicates that the target shall not report a GOOD status on PRINT commands or SLEW AND PRINT commands until the data are actually printed. A buffered mode of one indicates that the target may report a GOOD status on PRINT commands or SLEW AND PRINT commands as soon as the data have been transferred to the SCSI device buffer. The data from one or more commands may be buffered prior to printing. Buffered modes of 2H through 7H are reserved. 10.7 RESERVE UNIT and RELEASE UNIT Commands Peripheral Device Type: Printer Operation Code Type: Optional Operation Code: 16H and 17H, respectively Table 10-9 RESERVE UNIT and RELEASE UNIT Commands ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | 3rdPty | Third Party Device ID |Reserved| -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The RESERVE UNIT and RELEASE UNIT commands both use the command descriptor block shown in Table 10-9. 10.7.1 RESERVE UNIT Command. The RESERVE UNIT command (Table 10-9, operation code 16H) shall reserve the specified logical unit for the exclusive use by the requesting initiator or, if third-party reservation option is implemented, to another specified SCSI device. The reservation shall remain in effect until superceded by another RESERVE UNIT command from the initiator that made the reservation or until released by a RELEASE UNIT command from the same initiator, or a BUS DEVICE RESET message >From any initiator, or a "hard" RESET condition. The occurrence of the last two conditions is indicated by a sense key of UNIT ATTENTION on the next command following the condition. It is not an error to issue this command to a logical unit that is currently reserved to the requesting initiator. If the logical unit is previously reserved by another initiator, then the target shall either: (1) return a RESERVATION CONFLICT status (2) queue the reservation request and disconnect until all previously queued reservations have been released. When the logical unit is available, the target shall reconnect to perform the reservation If, after honoring the reservation, any other initiator then subsequently attempts to perform any command on the reserved logical unit other than a RESERVE UNIT command, which may be queued, or a RELEASE UNIT command, which shall be ignored, then the command shall be rejected with a RESERVATION CONFLICT status. The third-party reservation option for the RESERVE UNIT command allows an initiator to reserve a logical unit for another SCSI device. This option is intended for use in multiple-initiator systems that use the COPY command. Any target that implements the third-party reservation option shall also implement the third-party release option (see 10.7.2). If the third-party (3rdPty) bit is zero, then the third-party reservation option is not requested. If the 3rdPty bit is one and the third-party reservation option is implemented, then the RESERVE UNIT command shall reserve the specified logical unit for the SCSI device specified in the third-party device ID field. The target shall preserve the reservation until superceded by another RESERVE UNIT command from the initiator that made the reservation or until released by the same initiator, by a BUS DEVICE RESET message from any initiator, or by a "hard" RESET condition. The target shall ignore (i.e., return GOOD status) any attempt made by any other initiator to release the reservation. If the 3rdPty bit is one and the third-party reservation option is not implemented, then the target shall reject the RESERVE UNIT command with a CHECK CONDITION status and a sense key of ILLEGAL REQUEST. An initiator that holds a current reservation may modify that reservation (e.g., switch third-parties) by issuing another RESERVE UNIT command to the same logical unit. The superceding RESERVE UNIT command shall release the previous reservation state only when the new reservation is granted. A superceding reservation takes priority over any previously queued reservation request. 10.7.2 RELEASE UNIT Command. The RELEASE UNIT command (Table 10-9, operation code 17H) shall release the logical unit if it is currently reserved by the requesting initiator. It is not an error to attempt to release a logical unit that is not currently reserved to the requesting initiator. However, it shall not be released if it is reserved by another initiator. The third-party release option for the RELEASE UNIT command allows an initiator to release a logical unit that was previously reserved using the third-party reservation option (see 10.7.1). This option shall be implemented if the third-party reservation option is implemented. This option is intended for use in multiple-initiator systems that use the COPY command. If the third-party (3rdPty) bit is zero, then the third-party release option is not requested. If the 3rdPty bit is one and the target implements the third-party release option, then the target shall release the specified logical unit, but only if the reservation was made using the third-party reservation option by the initiator that is requesting the release and for the same SCSI device as specified in the third-party device ID field. If the 3rdPty bit is one and the target does not implement the third-party release option, then the target shall terminate the command with a CHECK CONDITION status and the sense key shall be set to ILLEGAL REQUEST. 10.8 MODE SENSE Command Peripheral Device Type: Printer Operation Code Type: Optional Operation Code: 1AH Table 10-10 MODE SENSE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Allocation Length | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The MODE SENSE command (Table 10-10) provides a means for a target to report its medium, logical unit, or peripheral device parameters to the initiator. It is a complementary command to the MODE SELECT command. The allocation length specifies the number of bytes that the initiator has allocated for returned MODE SENSE data. An allocation length of zero indicates that no MODE SENSE data shall be transferred. This condition shall not be considered as an error. Any other value indicates the maximum number of bytes that shall be transferred. The target shall terminate the DATA IN phase when allocation length bytes have been transferred or when all available MODE SENSE data have been transferred to the initiator, whichever is less. The MODE SENSE data (Table 10-11) contains a four-byte header, followed the vendor unique parameters, if any. .pa Table 10-11 MODE SENSE Data ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Sense Data Length | -----|-----------------------------------------------------------------------| 1 | Reserved | -----|-----------------------------------------------------------------------| 2 |Reserved| Buffered Mode | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | ============================================================================== | Vendor Unique Parameter(s) | ============================================================================== 0 _ n| Vendor Unique | | Parameter Byte(s) | ============================================================================== The sense data length specifies the length in bytes of the following MODE SENSE data that is available to be transferred during the DATA IN phase. The sense data length does not include itself. A buffered mode of zero indicates that the target does not report a GOOD status on PRINT commands or SLEW AND PRINT commands until the data are actually printed. A buffered mode of one indicates that the target may report a GOOD status on PRINT commands or SLEW AND PRINT commands as soon as the data have been transferred to the SCSI device buffer. The data from one or more commands may be buffered prior to printing. Buffered modes of 2H through 7H are reserved. .pa 10.9 STOP PRINT Command Peripheral Device Type: Printer Operation Code Type: Optional Operation Code: 1BH Table 10-12 STOP PRINT Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | Retain | -----|-----------------------------------------------------------------------| 2 | Vendor Unique | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The STOP PRINT command (Table 10-12) is used to halt printing on buffered devices in an orderly fashion. A retain bit of zero requests that the target data buffer be discarded; otherwise, the unprinted data is retained. The unprinted data may be recovered by use of the RECOVER BUFFERED DATA command, if supported. A subsequent PRINT command or SLEW AND PRINT command shall cause the remaining unprinted and unrecovered data to be printed followed by the data transferred by the subsequent command. The point at which printing is suspended by this command is peripheral-device specific and is not defined by this standard. .pa .fo Section 11 # 11. Group 0 Command Descriptions for Processor Devices The Group 0 commands for processor devices shall be as shown in Table 11-1. Table 11-1 Group 0 Commands for Processor Devices ============================================================================== Operation Code Type Command Name Section ------------------------------------------------------------------------------ 00H O TEST UNIT READY 7.1.1 01H V 02H V 03H M REQUEST SENSE 7.1.2 04H V 05H V 06H V 07H V 08H O RECEIVE 11.1 09H V 0AH M SEND 11.2 0BH V 0CH V 0DH V 0EH V 0FH V 10H V 11H V 12H E INQUIRY 7.1.3 13H V 14H V 15H V 16H V 17H V 18H O COPY 7.1.4 19H R 1AH R 1BH R 1CH O RECEIVE DIAGNOSTIC RESULTS 7.1.5 1DH O SEND DIAGNOSTIC 7.1.6 1EH R 1FH R ============================================================================== Key: M = Command implementation is mandatory. E = Command implementation is required for SCSI devices that support device-independent self-configuring software. O = Command implementation is optional. R = Operation code is reserved for future standardization. V = Operation code is available for vendor unique commands. .pa 11.1 RECEIVE Command Peripheral Device Type: Processor Devices Operation Code Type: Optional Operation Code: 08H Table 11-2 RECEIVE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Allocation Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Allocation Length | -----|-----------------------------------------------------------------------| 4 | Allocation Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The RECEIVE command (Table 11-2) transfers data from the target to the initiator. The allocation length specifies the number of bytes that the initiator has allocated for the returned data. An allocation length of zero indicates that no data shall be transferred. This condition shall not be considered as an error. Any other value indicates the maximum number of bytes that shall be transferred. The target shall terminate the DATA IN phase when allocation length bytes have been transferred or when all available data have been transferred to the initiator, whichever is less. .pa 11.2 SEND Command Peripheral Device Type: Processor Devices Operation Code Type: Mandatory Operation Code: 0AH Table 11-3 SEND Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Transfer Length | -----|-----------------------------------------------------------------------| 4 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The SEND command (Table 11-3) transfers data from the initiator to the target. The transfer length specifies the length in bytes of data that shall be sent during the DATA OUT phase. A transfer length of zero indicates that no data shall be sent. This condition shall not be considered as an error. .pa .fo Section 12 # 12. Command Descriptions for Write-Once Read-Multiple Devices 12.1 Group 0 Commands for Write-Once Read-Multiple Devices. The Group 0 commands for write-once read-multiple devices shall be as shown in Table 12-1. Table 12-1 Group 0 Commands for Write-Once Read-Multiple Devices ============================================================================== Operation Code Type Command Name Section ------------------------------------------------------------------------------ 00H O TEST UNIT READY 7.1.1 01H O REZERO UNIT 8.1.1 02H V 03H M REQUEST SENSE 7.1.2 04H R 05H V 06H V 07H O REASSIGN BLOCKS 8.1.3 08H O READ 12.1.1 09H V 0AH O WRITE 12.1.2 0BH O SEEK 8.1.6 0CH V 0DH V 0EH V 0FH V 10H V 11H V 12H E INQUIRY 7.1.3 13H V 14H V 15H O MODE SELECT 12.1.3 16H O RESERVE 8.1.8 17H O RELEASE 8.1.9 18H O COPY 7.1.4 19H V 1AH O MODE SENSE 12.1.4 1BH O START/STOP UNIT 8.1.11 1CH O RECEIVE DIAGNOSTIC RESULTS 7.1.5 1DH O SEND DIAGNOSTIC 7.1.6 1EH O PREVENT/ALLOW MEDIUM REMOVAL 8.1.12 1FH R ============================================================================== Key: M = Command implementation is mandatory. E = Command implementation is required for SCSI devices that support device-independent self-configuring software. O = Command implementation is optional. R = Operation code is reserved for future standardization. V = Operation code is available for vendor unique commands. .pa 12.1.1 READ Command Peripheral Device Type: Write-Once Read-Multiple and Read-Only Direct Access Operation Code Type: Optional Operation Code: 08H Table 12-2 READ Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number |Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 2 | Logical Block Address | -----|-----------------------------------------------------------------------| 3 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 4 | Transfer Length | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The READ command (Table 12-2) requests that the target transfer data to the initiator. The logical block address specifies the logical block at which the read operation shall begin. The transfer length specifies the number of contiguous logical blocks of data to be transferred. A Transfer Length of zero indicates that 256 logical blocks shall be transferred. Any other value indicates the number of logical blocks that shall be transferred. This command shall be terminated with a status of RESERVATION CONFLICT if any reservation access conflict (see 8.1.8) exists and no data shall be transferred. If any of the following conditions occur, this command shall be terminated with a CHECK CONDITION status, and if extended sense is implemented, the sense key shall be set as indicated in the following table. This table does not provide an exhaustive enumeration of all conditions that may cause the CHECK CONDITION status. .pa Condition Sense Key ---------------------------------------------- ---------------------------- Invalid logical block address ILLEGAL REQUEST (see note 1) Target reset or medium change since the last command from this initiator UNIT ATTENTION Unrecoverable read error MEDIUM ERROR Overrun or other error that might be resolved by repeating the command ABORTED COMMAND Attempt to read a blank or previously unwritten block BLANK CHECK (see note 2) NOTES: (1) The extended sense information bytes shall be set to the logical block address of the first invalid address. (2) The extended sense information bytes shall be set to the logical block address of the first blank block encountered. The data read up to that block shall be transferred. 12.1.2 WRITE Command Peripheral Device Type: Write-Once Read-Multiple Operation Code Type: Optional Operation Code: 0AH Table 12-3 WRITE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number |Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 2 | Logical Block Address | -----|-----------------------------------------------------------------------| 3 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 4 | Transfer Length | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The WRITE command (Table 12-3) requests that the target write the data transferred from the initiator to the medium. The logical block address specifies the logical block at which the write operation shall begin. The transfer length specifies the number of contiguous logical blocks of data that shall be written. A transfer length of zero indicates that 256 logical blocks shall be written. Any other value indicates the number of logical blocks that shall be written. This command shall be terminated with a status of RESERVATION CONFLICT if any reservation access conflict (see 8.1.8) exists and no data shall be written. If any of the following conditions occur, this command shall be terminated with a CHECK CONDITION status, and if extended sense is implemented, the sense key shall be set as indicated in the following table. This table does not provide an exhaustive enumeration of all conditions that may cause the CHECK CONDITION status. Condition Sense Key ---------------------------------------------- ---------------------------- Invalid logical block address ILLEGAL REQUEST (see note 1) Target reset or medium change since the last command from this initiator UNIT ATTENTION Overrun or other error that might be resolved by repeating the command ABORTED COMMAND Attempt to write a previously written block and blank checking is enabled (see 12.1.3) BLANK CHECK (see note 2) NOTES: (1) The extended sense information bytes shall be set to the logical Block Address of the first invalid address. (2) The extended sense information bytes shall be set to the logical block address of the first non-blank block encountered. .pa 12.1.3 MODE SELECT Command Peripheral Device Type: Write-Once Read-Multiple and Read-Only Direct Access Operation Code Type: Optional Operation Code: 15H Table 12-4 MODE SELECT Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Parameter List Length | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The MODE SELECT command (Table 12-4) provides a means for the initiator to specify medium, logical unit, or peripheral device parameters to the target. The parameter list length specifies the length in bytes of the MODE SELECT parameter list that shall be transferred from the initiator to the target. A parameter list length of zero indicates that no data shall be transferred. This condition shall not be considered as an error. The MODE SELECT parameter list (Table 12-5) contains a four-byte header, followed by zero or more eight-byte block descriptors, followed by the vendor unique parameters, if any. .pa Table 12-5 MODE SELECT Parameter List ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Reserved | -----|-----------------------------------------------------------------------| 1 | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | EBC | -----|-----------------------------------------------------------------------| 3 | Block Descriptor Length | ============================================================================== | Block Descriptor(s) | ============================================================================== 0 | Reserved | -----|-----------------------------------------------------------------------| 1 | Number of Blocks (MSB) | -----|-----------------------------------------------------------------------| 2 | Number of Blocks | -----|-----------------------------------------------------------------------| 3 | Number of Blocks (LSB) | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Block Length (MSB) | -----|-----------------------------------------------------------------------| 6 | Block Length | -----|-----------------------------------------------------------------------| 7 | Block Length (LSB) | ============================================================================== | Vendor Unique Parameter(s) | ============================================================================== 0 _ n| Vendor Unique | | Parameter Byte(s) | ============================================================================== An enable blank check (EBC) bit of zero disables blank checking of the medium during write operations. An EBC bit of one enables blank checking. If a non-blank block is found during a write operation, the command shall be terminated with a CHECK CONDITION status and the sense key shall be set to BLANK CHECK. For read-only direct-access devices, the EBC bit is reserved. The block descriptor length specifies the length in bytes of all the block descriptors. It is equal to the number of block descriptors times eight and does not include the vendor unique parameters, if any. A block descriptor length of zero indicates that no block descriptors shall be included in the parameter list. This condition shall not be considered as an error. Each block descriptor specifies the medium characteristics for all or part of a logical unit. Each block descriptor contains a number of blocks and a block length. The number of blocks field specifies the number of logical blocks to be formatted with the block length specified in the block descriptor. The block length field specifies the length in bytes of the logical block to be formatted. 12.1.4 MODE SENSE Command Peripheral Device Type: Write-Once Read-Multiple and Read-Only Direct Access Operation Code Type: Optional Operation Code: 1AH Table 12-6 MODE SENSE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Allocation Length | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The MODE SENSE command (Table 12-6) provides a means for a target to report its medium, logical unit, or peripheral device parameters to the initiator. It is a complementary command to the MODE SELECT command for support of medium that may contain multiple block lengths. The allocation length specifies the number of bytes that the initiator has allocated for returned MODE SENSE Data. An allocation length of zero indicates that no MODE SENSE data shall be transferred. This condition shall not be considered as an error. Any other value indicates the maximum number of bytes that shall be transferred. The target shall terminate the DATA IN phase when allocation length bytes have been transferred or when all available MODE SENSE data have been transferred to the initiator, whichever is less. The MODE SENSE data (Table 12-7) contains a four-byte header, followed by zero or more eight-byte block descriptors, followed by the vendor unique parameters, if any. .pa Table 12-7 MODE SENSE Data ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Sense Data Length | -----|-----------------------------------------------------------------------| 1 | Medium Type | -----|-----------------------------------------------------------------------| 2 | WP | Reserved | EBC | -----|-----------------------------------------------------------------------| 3 | Block Descriptor Length | ============================================================================== | Block Descriptor(s) | ============================================================================== 0 | Reserved | -----|-----------------------------------------------------------------------| 1 | Number of Blocks (MSB) | -----|-----------------------------------------------------------------------| 2 | Number of Blocks | -----|-----------------------------------------------------------------------| 3 | Number of Blocks (LSB) | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Block Length (MSB) | -----|-----------------------------------------------------------------------| 6 | Block Length | -----|-----------------------------------------------------------------------| 7 | Block Length (LSB) | ============================================================================== | Vendor Unique Parameter(s) | ============================================================================== 0 _ n| Vendor Unique | | Parameter Byte(s) | ============================================================================== The sense data length specifies the length in bytes of the following MODE SENSE data that is available to be transferred during the DATA IN phase. The sense data length does not include itself. Code values for the medium type field shall be assigned as follows: 00H Default (only one medium type supported) 01H _ 7FH Reserved 80H _ FFH Vendor unique An enable blank check (EBC) bit of zero indicates that blank checking of the medium during write operations is disabled. An EBC bit of one indicates that blank checking during write operations is enabled. For read-only direct- access devices, the EBC bit is reserved. A write protected (WP) bit of zero indicates that the medium is write enabled. A WP bit of one indicates that the medium is write protected. For read-only direct-access devices, the WP bit is reserved. The block descriptor length specifies the length in bytes of all the block descriptors. It is equal to the number of block descriptors times eight and does not include the vendor unique parameters, if any. A block descriptor length of zero indicates that no block descriptors shall be included in the parameter list. This condition shall not be considered as an error. Each block descriptor specifies the medium characteristics for all or part of a logical unit. Each block descriptor contains a number of blocks and a block length. The number of blocks field indicates the number of logical blocks that have the block length specified in the block descriptor. The block length field indicates the length in bytes of each logical block. .pa ?? 12.2 Group 1 Commands for Write-Once Read-Multiple Devices. The Group 1 commands for write-once read-multiple devices shall be as shown in Table 12-8. Table 12-8 Group 1 Commands for Write-Once Read-Multiple Devices ============================================================================== Operation Code Type Command Name Section ------------------------------------------------------------------------------ 20H V 21H V 22H V 23H V 24H V 25H E READ CAPACITY 8.2.1 26H V 27H V 28H M READ 12.2.1 29H V 2AH M WRITE 12.2.2 2BH O SEEK 8.2.4 2CH V 2DH V 2EH O WRITE AND VERIFY 12.2.3 2FH O VERIFY 12.2.4 30H O SEARCH DATA HIGH 8.2.7.1 31H O SEARCH DATA EQUAL 8.2.7.2 32H O SEARCH DATA LOW 8.2.7.3 33H O SET LIMITS 8.2.8 34H R 35H R 36H R 37H R 38H R 39H O COMPARE 7.2.1 3AH O COPY AND VERIFY 7.2.2 3BH R 3CH R 3DH R 3EH R 3FH R ============================================================================== Key: M = Command implementation is mandatory. E = Command implementation is required for SCSI devices that support device-independent self-configuring software. O = Command implementation is optional. R = Operation code is reserved for future standardization. V = Operation code is available for vendor unique commands. .pa 12.2.1 READ Command Peripheral Device Type: Write-Once Read-Multiple and Read-Only Direct Access Operation Code Type: Mandatory Operation Code: 28H Table 12-9 READ Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | RelAdr | -----|-----------------------------------------------------------------------| 2 | Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 3 | Logical Block Address | -----|-----------------------------------------------------------------------| 4 | Logical Block Address | -----|-----------------------------------------------------------------------| 5 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 6 | Reserved | -----|-----------------------------------------------------------------------| 7 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 8 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 9 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The READ command (Table 12-9) requests that the target transfer data to the initiator from the medium. The logical block address specifies the logical block at which the read operation shall begin. The transfer length specifies the number of contiguous logical blocks of data that shall be transferred. A transfer length of zero indicates that no data shall be transferred. This condition shall not be considered as an error. Any other value indicates the number of logical blocks that shall be transferred. This command shall be terminated with a status of RESERVATION CONFLICT if any reservation access conflict (see 8.1.8) exists and no data shall be transferred. If any of the following conditions occur, this command shall be terminated with a CHECK CONDITION status and, if extended sense is implemented, the sense key shall be set as indicated in the following table. This table does not provide an exhaustive enumeration of all conditions that may cause the CHECK CONDITION status. Condition Sense Key ---------------------------------------------- ---------------------------- Invalid logical block address ILLEGAL REQUEST (see note 1) Target reset or medium change since the last command from this initiator UNIT ATTENTION Overrun or other error that might be resolved by repeating the command ABORTED COMMAND Attempt to read a blank or previously unwritten block BLANK CHECK (see note 2) NOTES: (1) The extended sense information bytes shall be set to the logical block address of the first invalid address. (2) The extended sense information bytes shall be set to the logical block address of the first blank block encountered. The data read up to that block shall be transferred. 12.2.2 WRITE Command Peripheral Device Type: Write-Once Read-Multiple Operation Code Type: Mandatory Operation Code: 2AH Table 12-10 WRITE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | RelAdr | -----|-----------------------------------------------------------------------| 2 | Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 3 | Logical Block Address | -----|-----------------------------------------------------------------------| 4 | Logical Block Address | -----|-----------------------------------------------------------------------| 5 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 6 | Reserved | -----|-----------------------------------------------------------------------| 7 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 8 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 9 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The WRITE command (Table 12-10) requests that the target write the data transferred from the initiator to the medium. The logical block address specifies the logical block at which the write operation shall begin. The transfer length specifies the number of contiguous logical blocks of data that shall be transferred. A transfer length of zero indicates that no data shall be transferred. This condition shall not be considered as an error and no data shall be written. Any other value indicates the number of logical blocks that shall be transferred. This command shall be terminated with a status of RESERVATION CONFLICT if any reservation access conflict (see 8.1.8) exists and no data shall be written. If any of the following conditions occur, this command shall be terminated with a CHECK CONDITION status and, if extended sense is implemented, the sense key shall be set as indicated in the following table. This table does not provide an exhaustive enumeration of all conditions that may cause the CHECK CONDITION status. Condition Sense Key ---------------------------------------------- ---------------------------- Invalid logical block address ILLEGAL REQUEST (see note 1) Target reset or medium change since the last command from this initiator UNIT ATTENTION Overrun or other error that might be resolved by repeating the command ABORTED COMMAND Attempt to write a previously written block and blank checking is enabled (see 12.1.3) BLANK CHECK (see note 2) NOTES: (1) The extended sense information bytes shall be set to the logical block address of the first invalid address. (2) The extended sense information bytes shall be set to the logical block address of the first non-blank block encountered. .pa 12.2.3 WRITE AND VERIFY Command Peripheral Device Type: Write-Once Read-Multiple Operation Code Type: Optional Operation Code: 2EH Table 12-11 WRITE AND VERIFY Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | BytChk | RelAdr | -----|-----------------------------------------------------------------------| 2 | Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 3 | Logical Block Address | -----|-----------------------------------------------------------------------| 4 | Logical Block Address | -----|-----------------------------------------------------------------------| 5 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 6 | Reserved | -----|-----------------------------------------------------------------------| 7 | Transfer Length (MSB) | -----|-----------------------------------------------------------------------| 8 | Transfer Length (LSB) | -----|-----------------------------------------------------------------------| 9 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The WRITE AND VERIFY command (Table 12-11) requests that the target write the data transferred from the initiator to the medium and then verify that the data is correctly written. A byte check (BytChk) bit of zero causes the verification to be simply a medium verification (CRC, ECC, etc). A BytChk bit of one causes a byte-by- byte compare of data written to the peripheral device and the data transferred >From the initiator. If the compare is unsuccessful, the command shall be terminated with a CHECK CONDITION status and the sense key shall be set to MISCOMPARE. The logical block address specifies the logical block at which the write operation shall begin. The transfer length specifies the number of contiguous logical blocks of data that shall be transferred. A transfer length of zero indicates that no logical blocks shall be transferred. This condition shall not be considered as an error and no data shall be written. Any other value indicates the number of logical blocks that shall be transferred. .pa 12.2.4 VERIFY Command Peripheral Device Type: Write-Once Read-Multiple and Read-Only Direct Access Operation Code Type: Optional Operation Code: 2FH Table 12-12 VERIFY Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | BlkVfy | BytChk | RelAdr | -----|-----------------------------------------------------------------------| 2 | Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 3 | Logical Block Address | -----|-----------------------------------------------------------------------| 4 | Logical Block Address | -----|-----------------------------------------------------------------------| 5 | Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 6 | Reserved | -----|-----------------------------------------------------------------------| 7 | Verification Length (MSB) | -----|-----------------------------------------------------------------------| 8 | Verification Length (LSB) | -----|-----------------------------------------------------------------------| 9 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The VERIFY command (Table 12-12) requests that the target verify the data on the medium. A byte check (BytChk) bit of zero causes the verification to be simply a medium verification (CRC, ECC, etc). A BytChk bit of one causes a byte-by- byte compare of the data on the medium and the data transferred from the initiator. The data shall be transferred as it would be for a WRITE command. If the compare is unsuccessful, the command shall be terminated with a CHECK CONDITION status and the sense key shall be set to MISCOMPARE. A blank verify (BlkVfy) bit of one causes a verification that the blocks are blank. The logical block address specifies the logical block at which the verify operation shall begin. The verification length specifies the number of contiguous logical blocks of data or blanks that shall be verified. A verification length of zero indicates that no logical blocks shall be verified. This condition shall not be considered as an error. Any other value indicates the number of logical blocks that shall be verified. .fo Section 13 # 13. Command Descriptions for Read-Only Direct-Access Devices 13.1 Group 0 Commands for Read-Only Direct-Access Devices. The Group 0 commands for read-only direct-access devices shall be as shown in Table 13-1. Table 13-1 Group 0 Commands for Read-Only Direct-Access Devices ============================================================================== Operation Code Type Command Name Section ------------------------------------------------------------------------------ 00H O TEST UNIT READY 7.1.1 01H O REZERO UNIT 8.1.1 02H V 03H M REQUEST SENSE 7.1.2 04H R 05H V 06H V 07H R 08H O READ 12.1.1 09H V 0AH R 0BH O SEEK 8.1.6 0CH V 0DH V 0EH V 0FH V 10H V 11H V 12H E INQUIRY 7.1.3 13H V 14H V 15H O MODE SELECT 12.1.3 16H O RESERVE 8.1.8 17H O RELEASE 8.1.9 18H O COPY 7.1.4 19H V 1AH O MODE SENSE 12.1.4 1BH O START/STOP UNIT 8.1.11 1CH O RECEIVE DIAGNOSTIC RESULTS 7.1.5 1DH O SEND DIAGNOSTIC 7.1.6 1EH O PREVENT/ALLOW MEDIUM REMOVAL 8.1.12 1FH R ============================================================================== Key: M = Command implementation is mandatory. E = Command implementation is required for SCSI devices that support device-independent self-configuring software. O = Command implementation is optional. R = Operation code is reserved for future standardization. V = Operation code is available for vendor unique commands. .pa 13.2 Group 1 Commands for Read-Only Direct-Access Devices. The Group 1 commands for read-only direct-access devices shall be as shown in Table 13-2. Table 13-2 Group 1 Commands for Read-Only Direct-Access Devices ============================================================================== Operation Code Type Command Name Section ------------------------------------------------------------------------------ 20H V 21H V 22H V 23H V 24H V 25H E READ CAPACITY 8.2.1 26H V 27H V 28H M READ 12.2.1 29H V 2AH R 2BH O SEEK 8.2.4 2CH V 2DH V 2EH R 2FH O VERIFY 12.2.4 30H O SEARCH DATA HIGH 8.2.7.1 31H O SEARCH DATA EQUAL 8.2.7.2 32H O SEARCH DATA LOW 8.2.7.3 33H O SET LIMITS 8.2.8 34H R 35H R 36H R 37H R 38H R 39H O COMPARE 7.2.1 3AH O COPY AND COMPARE 7.2.2 3BH R 3CH R 3DH R 3EH R 3FH R ============================================================================== Key: M = Command implementation is mandatory. E = Command implementation is required for SCSI devices that support device-independent self-configuring software. O = Command implementation is optional. R = Operation code is reserved for future standardization. V = Operation code is available for vendor unique commands. .pa .fo Section 14 # 14. Status A status byte shall be sent from the target to the initiator during the STATUS phase at the termination of each command as specified in Tables 14-1 and 14-2 unless the command is cleared by an ABORT message, by a BUS DEVICE RESET message, or by a "hard" RESET condition. Table 14-1 Status Byte ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 |Reserved| Vendor Unique | Status Byte Code | V | ============================================================================== Table 14-2 Status Byte Code Bit Values ============================================================================== Bits of Status Byte ----------------------------- 7 6 5 4 3 2 1 0 Status(es) Represented ------------------------------------------------------------------------------ R V V 0 0 0 0 V GOOD R V V 0 0 0 1 V CHECK CONDITION R V V 0 0 1 0 V CONDITION MET/GOOD R V V 0 0 1 1 V Reserved R V V 0 1 0 0 V BUSY R V V 0 1 0 1 V Reserved R V V 0 1 1 0 V Reserved R V V 0 1 1 1 V Reserved R V V 1 0 0 0 V INTERMEDIATE/GOOD R V V 1 0 0 1 V Reserved R V V 1 0 1 0 V INTERMEDIATE/CONDITION MET/GOOD R V V 1 0 1 1 V Reserved R V V 1 1 0 0 V RESERVATION CONFLICT R V V 1 1 0 1 V Reserved R V V 1 1 1 0 V Reserved R V V 1 1 1 1 V Reserved ============================================================================== Key: R - Reserved bit V - Vendor unique bit .pa A description of the status byte codes is given below: GOOD. This status indicates that the target has successfully completed the command. CHECK CONDITION. Any error, exception, or abnormal condition that causes sense data to be set, shall cause a CHECK CONDITION status. The REQUEST SENSE command should be issued following a CHECK CONDITION status, to determine the nature of the condition. CONDITION MET. The SEARCH DATA commands shall return this status whenever a search condition is satisfied. This status does not break a chain of linked commands. The logical block address of the logical block that satisfies the search may be determined with a REQUEST SENSE command. BUSY. The target is busy. This status shall be returned whenever a target is unable to accept a command from an initiator. The normal initiator recovery action is to issue the command again at a later time. INTERMEDIATE. This status shall be returned for every command in a series of linked commands (except the last command), unless an error, exception, or abnormal condition causes a CHECK CONDITION status or a RESERVATION CONFLICT status to be set. If this status is not returned, the chain of linked commands is broken; no further commands in the series are executed. RESERVATION CONFLICT. This status shall be returned whenever an SCSI device attempts to access a logical unit or an extent within a logical unit that is reserved for that type of access to another SCSI device. .pa