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E P A S M Microprocessor assembler for the Intel 8749H Joseph L. Hora January 12, 1992 Version 1.3 EPASM Assembler October 11, 1990 Table of Contents I. Introduction . . . . . . . . . . . . . . . . . . . . . . 2 II. Loading EPASM on your system . . . . . . . . . . . . . . 4 III. Creating an assembly language program . . . . . . . . . 6 IV. EPASM assembler directives . . . . . . . . . . . . . . . 8 Description of assembler directives . . . . . . . . . . 8 ; . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 ORG . . . . . . . . . . . . . . . . . . . . . . . . 8 "label" . . . . . . . . . . . . . . . . . . . . . 8 CONST . . . . . . . . . . . . . . . . . . . . . . 9 INCLUDE . . . . . . . . . . . . . . . . . . . . 10 V. MCS-48 command notes . . . . . . . . . . . . . . . . . 12 VI. Assembling your program . . . . . . . . . . . . . . . . 15 command line options . . . . . . . . . . . . . . . . . 15 Running EPASM . . . . . . . . . . . . . . . . . . . . 16 VII. Error messages . . . . . . . . . . . . . . . . . . . 18 VII.1 Command, file, and DOS errors . . . . . . . . . 18 VII.2 EPASM assembly errors . . . . . . . . . . . . . 19 VIII. Using the EPROM programming device . . . . . . . . . 22 INVOICE . . . . . . . . . . . . . . . . . . . . . . . . . . 24 1 EPASM Assembler October 11, 1990 I. Introduction The EPASM program is a one-pass assembler that was written for the Intel 8749H EPROM as described in the Intel Microcontroller Handbook, using the MCS-48 instruction set. This assembler can also be used for other chips using this instruction set (8748H EPROM, 8048AH/8049AH/8050AH ROM, and 8035AHL/8039AHL/8040AHL CPU) as far as their memory structures are similar to the 8749H EPROM. This manual is not intended to be a reference for the MCS-48 instruction set or the above mentioned devices. Please refer to the Intel Microcontroller handbook for a complete description. The input to the EPASM program is a file containing "source code" which is the EPROM program. This contains the MCS-48 command mnemonics, labels, assembler directives, and comments. EPASM converts it into the machine code of the processor, the actual command numbers that will direct the processor to carry out the steps the programmer has specified. This machine code is saved to a file which then must be transferred to the processor using a EPROM "burner" or programming device. The output of EPASM is an object code module file. In this file are the encoded commands that were specified by the assembler language program. This program was written to construct an ASCII file suitable for the PROMPRO 7 EPROM Programming Unit, made by Logical Devices, Inc. The files have also been used to program EPROMs using the B&C Microsystems 1409 Universal (E)EPROM programmer. However, the file can also be passed to many other EPROM programming devices that support the same format. The file could also be converted by a program of your own to the proper format for your device. This program is distributed as shareware. It may be freely distributed to others, as long as it is in the form of the archived .ZIP file which contains all the separate files necessary for EPASM, and the files are not modified in any way. If you find this program useful, register your use of the program by sending $15 to Joseph Hora 46-1063 Emepela Way, Unit D Kaneohe, HI 96744-3975 When registering, you will receive the latest version of EPASM (without the annoying registration screen), a printed copy of the manual, and the source code for EPASM (written in Turbo Pascal 2 EPASM Assembler October 11, 1990 5.0). You will also be notified when updates of the program occur in the future. Questions and technical support can be obtained by mail at the above address, or by phone at (808) 956- 9848 weekdays 8am-5pm HST. Your registration entitles you to use this software on a single computer and to make as many copies of this software as you wish for backup purposes. Note: MCS-48 and the various chip names mentioned above and throughout this manual are registered trademarks of the Intel Corporation. The EPASM program and associated files are copyright 1990-92 by Joseph Hora. 3 EPASM Assembler October 11, 1990 II. Loading EPASM on your system Before doing anything else with your distribution disk, make a backup copy first. The approved EPASM release is archived using the PKZIP file archiving utilities, and is named "EPASM.ZIP" . This includes the following files: EPASM.EXE - the assembler program EPASM.DOC - this document INSTR.SET - the MCS-48 instruction set SAMPLE.ASM - a sample assembly language program INVOICE.DOC - the registration form for EPASM To install the assembler, these files must be extracted and placed in a directory of your choice. The following are instructions for various system options. Single floppy drive systems: First, make a backup of the distribution disk. Place the original EPASM (source) disk in drive A: and type diskcopy a: a: Wait until the computer is done reading the disk and asks you for the target disk. Remove the original disk and place a blank disk in drive A:, then type <RETURN>. If you have PKUNZIP and EPASM.ZIP on the same 360K or larger floppy disk with nothing else, there will be enough room to store all the original plus extracted files. At the DOS prompt, type pkunzip epasm and the files will be extracted to the default directory. Dual Floppy users: First, make a backup of the distribution disk. Place the original EPASM (source) disk in drive A: and a blank formatted disk (target) in drive B: and type diskcopy a: b: 4 EPASM Assembler October 11, 1990 Wait until the computer is done reading the disk and writing to the target disk. You can make an EPASM disk by doing the following: First, make sure you have PKUNZIP and EPASM on one disk, and place it in the A: drive. Place a blank formatted disk in the B: drive and type "B:" to change default to that drive. Then type a:pkunzip a:epasm and the files will be extracted and written to the disk in the B: drive. Hard disk users: See the above instructions to backup your copy of EPASM before you install the program on your hard drive. Place the disk with the files EPASM.ZIP and PKUNZIP in the A: drive. Make a subdirectory on your hard drive to place your EPASM files into, for example, type C:\>mkdir epasm (Type the commands above that are after the >). Change directory to that subdirectory C:\>cd epasm C:\EPASM> Then type C:\EPASM>a:pkunzip a:epasm and the files will be extracted and written to the directory you are currently in on the hard drive. 5 EPASM Assembler October 11, 1990 III. Creating an assembly language program You must create the source code for EPASM in a text editor program. This can be any program that allows you to save the file in "ASCII" or "DOS" format. This means just text, with no page breaks, printer commands, formatting codes or commands specific to the word processing program. For example, in WordPerfect, you can use the Ctrl-F5,1,1 command to save the document as a DOS text file. EPASM will create various output files, based on the text file containing commands it is given and the command line options (see Chapter VI.) These output files can be viewed using the "TYPE" command from the DOS command prompt. The files can also be read into the word processing program and viewed in the same way the source code can. This is most useful when the user is trying to track down errors in the source code. There are two element types in the program, assembler directives and MCS-48 commands. Assembler directives are commands that are processed during the assembly by the EPASM assembler. The second type are commands that are converted directly into machine code for the EPROM processor. These two types are discussed in the following chapters. Below is a short excerpt from a sample program written for this assembler: ; ; ; IDLE routine: remain here until interrupted ; IDLE mov R3,#80 ;select expander 0, disable chop mov a,#8F ;address " " outl P2,a ; " " " movd P7,a ;output slave idle state call riff ;reset interrupt-in-progress jmp IDLE ;jump to IDLE ; ; End of IDLE routine ; This short excerpt illustrates a number of characteristics of the source code. First, the simplest command is the semicolon character ";", the comment command. This simply instructs the assembler to ignore all the characters following that one on the 6 EPASM Assembler October 11, 1990 current line. It can be used at the beginning of the line to designate the entire line as a comment, or it can be at the end of a valid command. In the above example, it is used to space out the routine with blank lines, hold the title of the routine, and annotate each command line with a comment. This is usually a good practice, since even a small assembly language program is difficult to follow without a few comments explaining the code, even for the person who wrote the program! Note that there is a mix of uppercase and lower case characters in this example. EPASM treats upper and lower case letters to be equal. Therefore, the commands "mov" and "MOV" are treated in exactly the same way. The next assembler directive used is in the first non-comment line, the text "IDLE". This is being used as a "label", or a marker designating that line or address in the program. This allows the programmer to reference commands in the program without knowing the actual address of the command in the program memory. Notice at the end of the routine there is a "jmp IDLE" command, which will cause the EPROM to loop back to the beginning of the routine when it runs the program. The EPASM program determines the address of "IDLE" as it assembles the program. On the same line as the "IDLE" label is the MCS-48 command for the processor. Note that these words are all separated by a number of spaces. Any combinations of spaces and tabs may be used to separate the words of each line. The spacing can be chosen arbitrarily to make the program easy to read. In the above example, the first column is reserved for labels. This makes the labels easy to see and therefore easier to follow the flow of the program. The next two columns hold the command arguments, and the third column holds a comment for that line. This is a fairly standard format for assembly language programs. Another equally valid format would be to have the commands be in one column, as in the following: ; ; ; IDLE routine: remain here until interrupted ; IDLE mov R3,#80 ;select expander 0, disable chop mov a,#8F ;address " " outl P2,a ; " " " movd P7,a ;output slave idle state call riff ;reset interrupt-in-progress jmp IDLE ;jump to IDLE ; ; End of IDLE routine ; 7 EPASM Assembler October 11, 1990 IV. EPASM assembler directives This chapter describes the valid assembler directives for the EPASM program. An assembler directive is a command that does not directly generate machine code in the output file, but affects the way EPASM compiles the program. The following are the recognized assembler directives, and a description of each: ; ORG "label" CONST INCLUDE Description of assembler directives: ; the comment character. Directs EPASM to ignore all other characters following this one on the same line. ORG specifies the location of the start of the program in the processor's program memory. The default location if this directive is not used is zero. The correct syntax is ORG addr where "addr" is the desired starting address, in hexadecimal. "label" any word more that three characters long and less than nine characters which is intended to mark a location in memory. I have enclosed the word "label" in quotes, since there is no actual command that you invoke by typing "label", you simply use a word that is not a command and the assembler will interpret it as a label. The label cannot be the same as another of the assembler directives (such as ORG or CONST), or be the same as one of the MCS-48 commands (such as MOV or JMP). Note that since no upper and lower case distinctions are made, the label "IDLE" is treated the same as the label "idle". When the label appears as the first element of a line, that equates the label with the memory position of that line. 8 EPASM Assembler October 11, 1990 When the label appears in any other line after a valid MCS- 48 command, that means that label is being referenced. When the EPROM program is assembled, the address corresponding to the line where the label appears will be placed in that command. The label can be defined only once, but referenced many times. Below is a program excerpt where labels are used. The routine checks the test pins of the 8749H processor and takes actions based on their state. Notice the use of labels: the first label is "Main" which is referenced in a number of instructions. Other labels allow control of the program flow based on the conditions encountered. Example IV.1 Main JT0 Stat1 ;If T0 set, goto Stat1 JT1 Stat2 ;If not T0 and T1, go here Mov R1,#20 ;Neither T0 or T1, BankA<<<< Jmp StatEnd ;Exit Stat section Stat1 JNT1 Stat3 ; Mov R1,#00 ;If T1 also set, then WAIT Jmp Main Stat3 Mov R1,#40 ;T0 and not T1, so Bank B<<<< Jmp StatEnd ; Stat2 Mov R1,#60 ;not T0 and T1, so Bank C<<<< StatEnd Mov A,R1 ;Get current base address XRL A,R2 ;Compare to last base address JZ TakDat ;If same, go inc. counters MOV A,R1 ;Different bank this time MOV R2,A ;set "old" base address here IN A,P1 ;set old port reading equal MOV R3,A ; to current one IN A,P2 ;same for port 2 MOV R4,A JMP Main ;End of Main Program loop The processor running this program would repeat the loop, testing T1 and T2. If the current base address as the last time, the program jumps to the line designated by the "StatEnd". CONST This assembler directive is useful for equating hex constants with words. It is exactly like defining a label that references a constant, not a memory location. The syntax of the directive is CONST name value 9 EPASM Assembler October 11, 1990 For example, the program in example IV.1 above considers the memory as being divided up into 3 "banks": A, B, and C, at locations 20, 40, and 60 (hex). Instead of the statements above which explicitly specify these memory locations, one could define constants to make this more readable. If the following lines are included in the program file: ; ; Constants CONST BankA 20 ;Bank A: 32-63 decimal CONST BankB 40 ;Bank B: 64-95 decimal CONST BankC 60 ;Bank C: 96-127 decimal ; Then example IV.1 could be written as follows: Example IV.2 Main JT0 Stat1 ;If T0 set, goto Stat1 JT1 Stat2 ;If not T0 and T1, go here Mov R1,#BankA ;Neither T0 or T1, so Bank A<<<< Jmp StatEnd ;Exit Stat section Stat1 JNT1 Stat3 ; Mov R1,#00 ;If T1 also set, then WAIT Jmp Main Stat3 Mov R1,#BankB ;T0 and not T1, so Bank B<<<< Jmp StatEnd ; Stat2 Mov R1,#BankC ;not T0 and T1, so Bank C<<<< StatEnd Mov A,R1 ;Get current base address XRL A,R2 ;Compare to last base address JZ TakDat ;If same, go increment counters MOV A,R1 ;Different bank this time, reset MOV R2,A ;set "old" base address here IN A,P1 ;set old port reading equal MOV R3,A ; to current one IN A,P2 ;same for port 2 MOV R4,A JMP Main ;End of Main Program loop The main reason for having the CONST directive is for program clarity. It is much easier to understand what you are doing if you write data to "BankC" instead of "80". INCLUDE This directive causes EPASM to stop reading from the current file being assembled, open the file specified and assemble commands from that file into the program until the end of that file is reached, then return to the original program 10 EPASM Assembler October 11, 1990 and continue assembling. It is effectively the same as having those commands in the INCLUDE file in your program. The command syntax is INCLUDE [path]filename The file must be in the current directory, or the full path specified, or else EPASM will not be able to find the file and an error will be generated. This command is useful if you have a number of standard definitions or routines that you use in many programs. Then you can have a single file containing them and all the other programs you write can INCLUDE this file, so you don't have to have multiple copies of the routines in every file. Also, when editing the standard routines, you can then recompile the routines and the changes will be effective in all programs that use that file. The only limitation on the include file is that you cannot "nest" the include files. That is, you cannot have an "INCLUDE" file that has another "INCLUDE" command for yet another file. Also, when there is an error in the program after the include file, the line number reported will be the actual line number of the program file plus the number of lines in the include file. If the error is in the include file itself, the line number reported will be the line number of the error in the include file plus the number of lines ahead of it in the main program. To be certain of the line numbers, the best way is to look at the .WRK file created by EPASM (see chapter VI). This file will show all lines from the main program and the include file together, in the order assembled. 11 EPASM Assembler October 11, 1990 V. MCS-48 command notes The MCS-48 commands are stored in the file INSTR.SET. This should, for the purposes of EPASM, be the reference for the correct syntax of the commands, since they will be expected to be exactly as they are spelled in this file. Note that all the commands in the file INSTR.SET must be in upper case, since any file assembled will be converted to upper case before being compared to these commands. The commands in the program to be assembled can be in either upper or lower case, as discussed above. The file INSTR.SET is an ASCII file, with each line being the definition for one command. Comments can also be included, if they are preceded by a semicolon. Below are a few sample lines. ; ; JF0 $ B6 2 JF1 $ 76 2 JMP ! 04 2 MOV A,# 23 2 ;this command moves in the immediate word MOV A,PSW C7 1 MOV A,R0 F8 1 MOV A,@R0 F0 1 MOV A,@R1 F1 1 MOV A,T 42 1 The format of the line is first the command word(s), then an address or data indicator, if any, then the hex machine code for the command, then the number of machine cycles for that command. The data or address indicators are the "#" and the "$" characters, respectively, and they show that the command includes a byte of data or an address. For example, the command to move immediate data to the accumulator is given by the line MOV A,# 23 2 Since it contains the "#" character, it indicates that a second byte is required; namely, the data to be moved into the accumulator. So the correct usage of this command would be MOV A,#1C ;Move the value 28 (1C hexadecimal) to acc. Similarly, the "$" character indicates that an address is needed in the command. So in the command JF1 $ 76 2 12 EPASM Assembler October 11, 1990 the program will jump to the address given if flag 1 is set. The correct usage of this command is JF1 DONE ;if flag set, jump to DONE where DONE is a label that is defined elsewhere in the program. Note that when the address is given by an eight-bit value, the location of DONE must be on the same memory page as the JF1 command, or else the jump will not be performed properly. The "!" character is used for the JMP and the CALL commands, which have a 11-bit address (in order to cover the entire 2K address space). The upper three bits of the address are encoded into the first byte of the command. This differs from the address byte in commands using the "$" character, which is just the second byte and therefore is limited to eight bits. EPASM treats these two commands specially and encodes the address automatically. Other commands have no data or address information, and are completely specified in the INSTR.SET file. For example, MOV A,@R1 F1 1 specifies the command to move data memory contents into the accumulator (register R1 has been previously loaded with the desired address). The correct usage of this command is MOV A,@R1 ;Move register-addressed data into acc. almost precisely as it appears in INSTR.SET. Because the INSTR.SET file is in ASCII format and read into the EPASM program every time it is executed, the INSTR.SET file can be edited to change the syntax of the commands, if desired. This is not usually recommended, since it is good to keep the command names similar to the MCS-48 commands for clarity. However, if you wish to program for a different EPROM with a different command set, one could simply change the file INSTR.SET to contain the commands in the alternate instruction set. The only restriction is that the CALL and JMP commands cannot be changed, since they are handled in a special way. Also, new commands with the "!" character cannot be added, since it requires changes in the EPASM program. Of course, if you have registered your copy of EPASM and have the source code, you can alter the assembler program for different devices. Another feature of EPASM is the ability to do simple arithmetic within the statement with hexadecimal numbers. The allowed operations are addition and subtraction. For example, say that you wanted to move the value 8C into the accumulator. The command would be 13 EPASM Assembler October 11, 1990 MOV A,#8C ; fill accumulator with value Now say that you wanted to move a number that was 7 larger than 8C. The correct command would be MOV A,#8C+07 ;fill accumulator with 7 greater than 8C This expression is evaluated during the assembly, and the correct constant value (147, or 93 hexadecimal) is placed in that memory location. So the command is equivalent to MOV A,#93 ;fill accumulator with 93 hex Since the expression is evaluated before the .OBJ output file is written, the statement will not add to the object code file length, or slow the program down. This feature is useful when you don't feel like doing the math operaation, or when you want to show the relationship between constants. 14 EPASM Assembler October 11, 1990 VI. Assembling your program Once the program has been written and saved to disk as an ASCII or "DOS" format text file, it is ready to be assembled by EPASM. The following is the command syntax for the assembler: epasm progname [-w -e -b -l -h] [filename] The "progname" above should be the file name of the ASCII file which contains the assembly language program you wish to assemble. It can be just the file name, or the full path if the file is not in the default directory. The extension ".ASM" is assumed if none is used. Be sure not to use the extension .TMP, because EPASM uses this for a temporary file, and later erases it. If you have another file with the same root name as your program and this extension, it will be erased. The command line options are: -w : create a "work" file, showing the program memory address, the assembled commands, and the original command from the input file source code. This is extremely useful when debugging the program, to see where the error is occurring and what the EPASM program is trying to do with the commands it is given. The default file name is the original name, with the extension ".WRK". -e : create an error listing file. This is a file containing all the error messages generated when running EPASM. These messages are also printed to the screen, but may come too fast to see them all. The default file name is the original file name with the extension ".ERR". -b : in addition to the ASCII object module created whenever EPASM successfully assembles a file, a binary file containing the machine code can also be created using this option. The binary file is a non-printable file which is 2K bytes in length and contains no format characters, checksums, etc, just the machine code in binary format. This file may be useful when a EPROM programming device may require a different format than the default .OBJ module normally created by EPASM. This binary file can be read easily into a conversion program that the user would write to output the proper format. The default name for this file is the original name and the extension ".BIN". 15 EPASM Assembler October 11, 1990 -l : this option creates a label listing output file that may also be useful for debugging purposes. This file contains a list of the program addresses and the machine code to be placed in that address. Labels are indicated by a carat (^) followed by an ASCII character for identification. At the end of the program will be a listing of all the labels used and the characters used to identify them in the listing above it. This output was mainly used during the development of EPASM, but it can also be useful as a debugging tool. The default name for this file is the original file name plus the extension ".LAB". -h : This option creates a "Hex" output file, which is an ASCII file with the assembled commands listed in hexadecimal form, 16 bytes per line (32 characters). This is basically the .OBJ format without the header information and the checksum. See chapter VIII. Note that when using command line switches, either upper case or lower case can be used, so that "-E" is the same as "-e". Also, the DOS switch character can be used (e.g., "/E"). Running EPASM When EPASM is run without any arguments, the program simply lists the command format and gives a short reminder of the command line options. To do this, just type C> EPASM (Note: in this example and those below, the "C>" represents the DOS prompt and should not be typed.) The EPASM program must be in the default directory, or a directory that is accessible via the current DOS PATH defined. The file INSTR.SET must be in the default directory or the same directory as EPASM, otherwise the error "Instruction set not found" will be generated. To assemble a program, type EPASM plus the file name to assemble. For example, if you wish to assemble the file SAMPLE.ASM which is included with this documentation, type C> EPASM SAMPLE The extension ".ASM" is assumed, and need not be entered. If you wish to assemble a file called SAMPLE.TST, just type C> EPASM SAMPLE.TST If you use command line switches, separate them with spaces from the rest of the command and from each other. For example, if you want to create a "work" file and an error listing (if there are 16 EPASM Assembler October 11, 1990 any errors in the program), type C> EPASM SAMPLE -E -W If there are errors, the files SAMPLE.ERR and SAMPLE.WRK will be created. If there are no errors, the files SAMPLE.WRK and SAMPLE.OBJ will be created. If you wish to specify different file names for the output files, the names can be included after the switch. For example, if we want to assemble the file SAMPLE.ASM, but want the work file name to be WORK.SMP, and create in addition to SAMPLE.OBJ a binary output file, we would type C> EPASM SAMPLE -W WORK.SMP -B While the EPASM program is running, it will notify you of errors it encounters by printing a message to the screen. If errors are encountered, no .OBJ, .HEX or .BIN output files are generated. If no errors are encountered, an .OBJ file will be created, along with a .BIN or .HEX file if the proper command line switch is used. An .ERR file will not be created, even if one is specified using the command line switch. If you wish to stop the assembly at any time, just press any key. The program will suspend the assembly and ask if you wish to abort. Type "Y" if you want to stop. This feature means that you can't "type ahead" the next DOS commands after EPASM, but the ability to terminate the assembly is very useful, mostly when EPASM finds errors and you do not want the assembler to bother with the rest of the file until you have gone back and corrected the errors. The file SAMPLE.ASM is included with this release to mainly illustrate the proper syntax and structure of an .ASM program, not to show good or useful programming technique. 17 EPASM Assembler October 11, 1990 VII. Error messages The first section below summarizes some of the errors that may occur in the command used to start EPASM from DOS, and errors in finding the proper files necessary to run EPASM. The second section describes the error messages given by EPASM when it finds errors in the program it is assembling. Tips are given as to what to do to correct the errors. VII.1 Command, file, and DOS errors Bad command or file name Make sure that you typed EPASM correctly, and that the EPASM.EXE program is in the current directory, or accessible via the PATH you have currently defined. Instruction set file INSTR.SET not found The file INSTR.SET is not in the default directory or cannot be found in the directories defined in the current DOS PATH. Make sure you have copied it from the distribution disk to the proper directory. Error in command line parameter You used an invalid combinations of switches and file names in the command line when you ran EPASM. See chapter VI for instructions on using the command line switches and file names. File not found Path not found The file name you specified is not correct, or it is not in the directory you specified, or that directory does not exist. Check the file names used in the command line, and in the INCLUDE files used, if any. Disk is write-protected If your files are on a floppy drive, make sure the write 18 EPASM Assembler October 11, 1990 protect tab is not on (for a 5 1/4" disk) or in the proper position (covering the hole in the 3.5" disk). Drive not ready Make sure the disk is in the drive specified, and the disk is locked in for reading. VII.2 EPASM assembly errors The following are error messages generated by EPASM when it finds errors in the program it is assembling. The error message will be printed out, followed by some of the offending text, and a line number. Often if a line has an error in it, two different error messages will be created, as EPASM tries to interpret the code in different ways. When the problem is solved, both messages will go away. The error detection in EPASM can only detect certain errors. It cannot, of course, diagnose logical errors that will cause your program to not work as you expect after you have "burned" the program into your EPROM. Invalid constant character The text encountered is being interpreted as a hexadecimal constant, and there was an error in converting the number. You may be trying to define a label that is two or fewer characters in length (a label must be three to eight characters long), or you mistyped the constant (you entered 8L when you intended 8C). Hex constant overflow The assembler is expecting a hexadecimal constant in that location, but the number there is over two digits in length (constant limits are 00 to FF hexadecimal). Invalid jump command The jump command entered is not a valid MCS-48 jump command. 19 EPASM Assembler October 11, 1990 Syntax error The command used on the line is not a valid MCS-48 command. Most likely you have misspelled the command, or the assembler is attempting to evaluate a label as a command. Make sure there are spaces or tabs separating the elements in a line. Call instruction cannot be located at [address] The CALL instruction cannot be located at addresses 2046- 2047 or at 4094-4095. You must change your program so that these statements do not fall on these addresses. Conditional jump at [address] cannot reach destination The conditional jump commands (e.g., JC, JF0, etc.) can only jump to addresses on the same 256-byte memory page, since the address used in the command is only 8 bits. The program is trying to jump to a label (address) on another page. You must change the program so that either the conditional jump and the destination are on the same page, or rewrite the code so that you jump across the page boundary (the CALL and JMP commands are not restricted to one page, they can jump directly to any location within the 2K program memory). Unresolved label You have referenced a label somewhere, but never defined its location (you define a label by putting it as the first element in some line). Either you forgot to define it, or misspelled it, either here or where it was defined. Warning: cannot nest INCLUDE files Your INCLUDE file contains another INCLUDE file. This is not allowed: call the second INCLUDE file from the main program. The second INCLUDE file will be ignored, and the assembly will continue. Warning: error opening INCLUDE file The INCLUDE file you specified could not be found. The INCLUDE file must be in the default directory, or must be specified by the full path name. The assembly will continue, but without the information in the INCLUDE file. Check the location of the file. 20 EPASM Assembler October 11, 1990 Work file error There was an error opening or deleting the work file specified (or the default work file name, if none explicitly chosen). EPASM first creates a work file with the extension .TMP, then at the end, erases this and makes a work file with the extension .WRK, or whatever you have specified. Be sure not to have any other files in the directory with the extension .TMP, or they may be erased! 21 EPASM Assembler October 11, 1990 VIII. Using the EPROM programming device The procedure that you use to program or "burn" the EPROM will vary greatly, depending on the device being used. In most cases you will be able to send the programming device a file of commands, which will direct the device to program the EPROM. This file is one of the output files from the EPASM program which contains your assembled code, either the default .OBJ file (which is the most common case), or the hex or binary files containing the same program in different format. Some programming devices (such as the PROMPRO-7) require that you communicate with it using a terminal emulator program. In this case, the emulator program has to have an "upload" command to send a file to the device. Other devices come with their own software drivers, such as the B&C Microsystems 1409 Universal programmer. With this device, the file can be read in and sent directly using commands from the driver program. There are three output file options in the EPASM program. The default .OBJ files are in Intel hex format. Each line of the file has the following information (all numbers in hexadecimal): INTEL hex format # of ASCII Characters Description 1 the colon character (:) 2 number of data bytes N in record (00 for end record) 4 the starting address of where the data bytes are to be located 2 00=program data in line, 01=end of file record N*2 the program data to be loaded into the EPROM 2 checksum (two's compliment of the sum of the bytes after the colon character, modulo 256) EPASM always sets N above equal to 10H (16 decimal). Another format option is the binary file, which contains the program to be loaded into the EPROM with no formatting information, just the bytes starting at address 0 and going to the end of the program memory, for a total of 2048 8-bit bytes of data. The locations from the end of the assembled program to the 22 EPASM Assembler October 11, 1990 end of the program memory space will be filled with zeros. A final format is the ASCII hex file, which contains the ASCII representation of the hex data to be loaded into the EPROM. This is just the same as the Intel file, except only the program data is in the file, there is no header information or end record. The data for program starting at address 0 going to the end of the program are included in the file. Sixteen program memory values are written per line (32 ASCII hex digits). 23 EPASM Assembler October 11, 1990 INVOICE Remit to: Joseph Hora 46-1063 Emepela Way, Unit D Kaneohe, HI 96744-3975 Questions and technical support number: (808) 956-9848 internet: hora@galileo.ifa.hawaii.edu From: ________________________________________________ ________________________________________________ ________________________________________________ ________________________________________________ Enclosed is $15.00 ( Check ___ Money Order ___ P. Order ___) for registration of EPASM. Please send me the latest version of the EPASM program and example files, a printed version of the manual, and the source code for the EPASM program (in Turbo Pascal 5.0), and put me on the mailing list for future updates and extensions to the EPASM program. 24