IRIX Base Documentation 2001 May

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sssseeeerrrriiiiaaaallll((((7777)))) sssseeeerrrriiiiaaaallll((((7777)))) NNNNAAAAMMMMEEEE serial - serial communication ports SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS ////ddddeeeevvvv////ttttttttyyyy<ttttyyyyppppeeee><ppppoooorrrrttttnnnnoooo> DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN All Silicon Graphics systems have two or more general purpose serial ports. These ports can be used to connect terminals, printers, modems, other systems, or graphical input devices such as a tablet or dial and button box. Each line can be independently set to run at any of several speeds. Various character echoing and interpreting parameters can also be set. See _s_t_t_y(1) and _t_e_r_m_i_o(7) for details on the various modes. Details of the serial ports found on optional add-on boards are given elsewhere. The Audio/Serial Option for CHALLENGE/Onyx provides six high-speed serial ports, see _a_s_o_s_e_r(7) for more information. The CDSIO VME board provides six serial ports; see _c_d_s_i_o(7) for more information. Special files for the serial ports exist in the /_d_e_v directory. These files are named ttttttttyyyy<ttttyyyyppppeeee><ppppoooorrrrttttnnnnoooo>, where ttttyyyyppppeeee is one or more characters indicating the type of interface to the hardware that this file provides, and ppppoooorrrrttttnnnnoooo is a number identifying the physical port. The descriptions below indicate among other things which hardware signals are used by each port type. For more details on this see SOFTWARE USAGE below. Currently supported types include: _dddd e.g. ttyd1. This is the most basic serial port type. It supports TD/RD only. _mmmm e.g. ttym1. This port type provides modem control. It supports TD/RD and DCD/DTR. _ffff e.g. ttyf1. This port type provides modem and flow control. It supports TD/RD, DCD/DTR and RTS/CTS. The following types are supported on O2, OCTANE, Origin2000/200, Onyx2 and Challenge/Onyx systems: _cccc e.g. ttyc1. This port type provides a raw character device interface to the hardware. It is intended for applications which wish to do bulk data transfer with minimal overhead and no data interpretation. Since this is not a streams device and no line discipline exists, streams or line discipline related ioctl commands may fail or silently have no effect. See cserialio(7) for details. This port type supports only TD/RD by default but RTS/CTS flow control may be enabled via ioctl if the hardware supports it. _4444_dddd e.g. tty4d1. This port type enables RS422 (Appletalk) mode. It uses TxD+/-, RxD+/-. On Challenge/Onyx, every 4th port (tty4d4, tty4d8, etc.) is hardwired to RS422 and other ports are hardwired to RS232, so this port type only exists for every 4th port. PPPPaaaaggggeeee 1111 sssseeeerrrriiiiaaaallll((((7777)))) sssseeeerrrriiiiaaaallll((((7777)))) _4444_ffff e.g. tty4f1. This port type enables RS422 (Appletalk) mode including the handshake signals. It uses TxD+/-, RxD+/-, HSKo and HSKi. On Challenge/Onyx, every 4th port (tty4d4, tty4d8, etc.) is hardwired to RS422 and other ports are hardwired to RS232, so this port type only exists for every 4th port. _mmmm_iiii_dddd_iiii e.g. ttymidi1. This port type provides a midi interface to the serial device. See midi(3). The following type is supported on O2, OCTANE, Onyx2 and Origin2000/200 systems: _uuuu_ssss e.g. ttyus1. This port type provides a user mapped interface to the hardware, allowing reading and writing of bytes without any system call overhead. Use of this port requires installation of the react.sw.usio subsystem of REACT/Pro. See usio(3) for details. The ppppoooorrrrttttnnnnoooo component of the tty filename identifies the actual hardware accessed by the device file. All tty files with the same port number access the same hardware, i.e. ttyd1, ttyc1 and ttymidi1 all access the same physical port. A given tty device may be opened any number of times, but only one interface type may be opened to the same physical port at a time, e.g. if ttyd1 is open, access will be denied to ttyf1 or ttyc1. On Onyx2 systems with console set to d, and on Origin2000 and Origin200 systems, the console port and its twin are guaranteed to be ports 1 and 2, all other ports are dynamically assigned port numbers as per the whims of ioconfig(1). It may be necessary to obtain the absolute path of the port in the filesystem by resolving links until a true device is found in order to determine where on the machine the port is actually located. CCCCOOOONNNNNNNNEEEECCCCTTTTOOOORRRRSSSS AAAANNNNDDDD PPPPIIIINNNN AAAASSSSSSSSIIIIGGGGNNNNMMMMEEEENNNNTTTTSSSS There are five different types of connectors found on various 4D models. Note that in terms of connectors and pin assignments, the Challenge S is identical to the Indy and both Challenge M and Power Challenge M are equivalent to the Indigo2. The DB-9 male serial port connectors on O2, OCTANE, Onyx2, Origin2000 and Origin200 systems have the following IBM(R) PC/AT(tm)-like pin assignments: ------------------- \ 1 2 3 4 5 / \ 6 7 8 9 / --------------- Pin Name Description ________________________________ 1 DCD Data Carrier Detect 2 RD Receive Data 3 TD Transmit Data 4 DTR Data Terminal Ready 5 GND Signal Ground ||||||| ||||||| PPPPaaaaggggeeee 2222 sssseeeerrrriiiiaaaallll((((7777)))) sssseeeerrrriiiiaaaallll((((7777)))) 6 - reserved 7 RTS Request To Send 8 CTS Clear To Send 9 - reserved |||| |||| The ports on OCTANE, Onyx2, Origin2000 and Origin200 systems can be set by software to an Appletalk-compatible RS-422-like mode, in which they have the following pin assignments: Pin Name Description _____________________________ 1 - reserved 2 RxD- Receive Data - 3 TxD- Transmit Data - 4 TxD+ Transmit Data + 5 GND Signal Ground 6 RxD+ Receive Data + 7 HSKo Output Handshake 8 HSKi Input Handshake 9 - reserved ||||||||||| ||||||||||| The DB-9 female serial port connectors, which are found on the CHALLENGE and Onyx systems, have the following pin assignments. ------------------- \ 5 4 3 2 1 / \ 9 8 7 6 / --------------- Pin Name Description ________________________________ 2 TD Transmit Data 3 RD Receive Data 4 RTS Request To Send 5 CTS Clear To Send 7 SG Signal Ground 8 DCD Data Carrier Detect 9 DTR Data Terminal Ready ||||||||| ||||||||| The CHALLENGE and Onyx systems provide an RS-422 port. This RS-422 port uses a DB-9 female serial connector and has the following pin assignments. Pin Name Description ________________________________ 1 DTR Data Terminal Ready 2 TxD- Transmit Data - 3 RxD- Receive Data - 4 DCD Data Carrier Detect 5 CTS Clear To Send 6 SG Signal Ground 7 TxD+ Transmit Data + ||||||||| ||||||||| PPPPaaaaggggeeee 3333 sssseeeerrrriiiiaaaallll((((7777)))) sssseeeerrrriiiiaaaallll((((7777)))) 8 RxD+ Receive Data + 9 RTS Request to send || || In order to support peripherals that draw power from the host system, the CHALLENGE and Onyx systems provide two powered-peripheral serial ports. These ports have a DIN-8 connector. The powered ports share the tty2 and tty3 signal lines with the standard DB-9 connectors; if the DB-9 connector for tty2 is already in use, you cannot use the powered peripheral connector for tty2. Similarly, if tty3's DB-9 connector is connected to a peripheral, the powered peripheral port connected to the tty3 signal lines cannot also be used. The powered peripheral ports have the following pin assignments. __---__ / 2 \ /4 5\ / \ ( 1 8 3 ) \ / \ 6 7 / ---___--- Pin Name Description __________________________________ 1 DTR Data Terminal Ready 2 CTS Clear To Send 3 STEREO Stereo field sync 4 RD Receive Data 5 TD Transmit Data 6 SG Signal Ground 7 GND Ground point 8 V10P 10V supply |||||||||| |||||||||| The DIN-8 serial port connectors on the Indigo, Indy, Indigo2, Challenge S, Challenge M, Power Challenge M, and the MENET 4-Enet, 6-serial board (XT-FE-4TX-6A) have the following pin assignments. --------- / 8 7 6 \ ( 5 4 3 ) \ 2 1 / --------- 4D Compatible Pin Assignments (RS-232) _________________________________________ Pin Name Description _________________________________________ 1 DTR Data Terminal Ready 2 CTS Clear To Send 3 TD Transmit Data 4 SG Signal Ground 5 RD Receive Data ||||||| ||||||| PPPPaaaaggggeeee 4444 sssseeeerrrriiiiaaaallll((((7777)))) sssseeeerrrriiiiaaaallll((((7777)))) 6 RTS Request To Send 7 DCD Data Carrier Detect 8 SG Signal Ground ||| ||| Macintosh SE Compatible Pin Assignments (RS-422) _________________________________________________ Pin Name Description _________________________________________________ 1 HSKo Output Handshake 2 HSKi Input Handshake Or External Clock 3 TxD- Transmit Data - 4 GND Signal Ground 5 RxD- Receive Data - 6 TxD+ Transmit Data + 7 GPi General Purpose Input 8 RxD+ Receive Data + |||||||||| |||||||||| SSSSOOOOFFFFTTTTWWWWAAAARRRREEEE UUUUSSSSAAAAGGGGEEEE The set of signals that are actually used depends upon which form of the device was opened. If the ttttttttyyyydddd name was used, only TTTTDDDD, RRRRDDDD, and SSSSGGGG signals are meaningful. These three signals are typically used with "dumb" devices that either do not need any sort of data flow control or use software flow control (see the description of the iiiixxxxoooonnnn, iiiixxxxaaaannnnyyyy, and iiiixxxxooooffffffff options in _s_t_t_y(1) for more information on setting up software flow control). If the ttttttttyyyymmmm device is used, the DDDDCCCCDDDD, and DDDDTTTTRRRR signals are also used. These signals provide a two way handshake for establishing and breaking a communication link with another device and are normally used when connecting via a modem. When the port is initially opened, the host asserts the DDDDTTTTRRRR line and waits for the DDDDCCCCDDDD line to become active. If the port is opened with the OOOO____NNNNDDDDEEEELLLLAAAAYYYY flag, the open succeeds even if the DDDDCCCCDDDD line is not active. A hangup condition occurs if the DDDDCCCCDDDD line transitions from active to inactive. See _o_p_e_n(2), and _t_e_r_m_i_o(7) for more information. If the ttttttttyyyyffff device is used, all of the signals are used. The additional signals provide for full hardware flow control between the host and the remote device. The RRRRTTTTSSSS line is asserted by the host whenever it is capable of receiving more data. The CCCCTTTTSSSS line is sampled before data is transmitted and if it is not active, the host suspends output until it is. The DIN-8 serial port connectors on the Indy, Challenge S, Indigo2, Challenge M, Power Challenge M, and MENET 4-Enet, 6-serial board (XT-FE- 4TX-6A) can be used to communicate with serial devices using RS-422 protocol. User can use the stream ioctl commands, SSSSIIIIOOOOCCCC____EEEEXXXXTTTTCCCCLLLLKKKK and SSSSIIIIOOOOCCCC____RRRRSSSS444422222222, defined in /_u_s_r/_i_n_c_l_u_d_e/_s_y_s/_z_8_5_3_0._h to switch between internal/external clock and RS-232/RS-422 protocols. Another command that can be useful is SSSSIIIIOOOOCCCC____IIIITTTTIIIIMMMMEEEERRRR; it informs the driver how long it should buffer up input data, in clock ticks, before sending them upstream. Data can sometimes be sent upstream before, but never after, this time limit. This feature reduces the cpu cost of receiving large amounts of data by sending data upstream in large chunks. This duration can also be configured into the kernel by tuning the duart_rsrv_duration variable. On Origin, Onyx2, O2 and Octane systems, the serial hardware sets an input timer based on the value passed in through SIOC_ITIMER. For PPPPaaaaggggeeee 5555 sssseeeerrrriiiiaaaallll((((7777)))) sssseeeerrrriiiiaaaallll((((7777)))) soft flow control, this input timer may result in excessively slow response to an XOFF request since an XOFF char is not detected by the software until the hardware timer expires. If soft flow control skid is unacceptably large, it may be necessary to reduce the latency of the hardware input timer by reducing the value passed to SIOC_ITIMER. SSSSUUUUPPPPPPPPOOOORRRRTTTTEEEEDDDD SSSSPPPPEEEEEEEEDDDDSSSS The serial ports of all SGI systems support several standard rates up through 38400 bps (see _t_e_r_m_i_o(_7) for these standard rates). The serial ports on O2, OCTANE, Origin2000, Onyx2 and Origin200 systems also support bit rates up through 115200 bps, including the following rates: 31250 57600 76800 115200 Many other rates, up to 460800, can be set. The accuracy of actual baud rate set is guaranteed to be within 2.5% of the desired rate. If this condition cannot be met, the command (ioctl or stty) will fail. However, performance at baud rates above 115200 is not guaranteed, and their use is not officially supported. At baud rates above 38400, cable length and quality become quite important. These rates are more likely to work in RS-422 mode, on systems that support it. CCCCHHHHAAAALLLLLLLLEEEENNNNGGGGEEEE LLLL////XXXXLLLL AAAANNNNDDDD OOOONNNNYYYYXXXX PPPPOOOORRRRTTTT CCCCOOOONNNNFFFFIIIIGGGGUUUURRRRAAAATTTTIIIIOOOONNNN By default, Onyx and CHALLENGE L/XL systems enable only the serial ports of the master IO4. To enable the serial ports on other IO4 boards, a vector line must be added for the epcserial device to /_v_a_r/_s_y_s_g_e_n/_s_y_s_t_e_m/_i_r_i_x._s_m. The following vector line configures the serial ports on the IO4 in slot 13 as tty45, tty46, and tty47: VECTOR: bustype=EPC module=epcserial unit=1 slot=13 The first two options (bustype and module) are mandatory and tell _l_b_o_o_t(1M) that you're configuring serial ports. The uuuunnnniiiitttt option specifies which set of tty names should be used for this set of ports: unit 1 corresponds to the logical devices tty45, tty46, and tty47; unit 2 represents devices tty49, tty50, and tty51; unit 3 specifies devices tty53, tty54, and tty55. Finally, the ssssllllooootttt option indicates which IO4 board contains the ports that should be mapped. Each board must have its own vector line. Configuring one IO4 board's serial ports has no effect on any of the other boards. After iiiirrrriiiixxxx....ssssmmmm has been updated, the _a_u_t_o_c_o_n_f_i_g(1M) command should be issued to reconfigure the kernel. It may also be necessary to execute _M_A_K_E_D_E_V(1M) in order to build device files for the new ports. If the system is unable to honor the VECTOR line for some reason (if, for example, the specified slot is invalid), a warning message is written to /_v_a_r/_a_d_m/_S_Y_S_L_O_G. These warning messages contain the string eeeeppppccccsssseeeerrrriiiiaaaallll, in order to facilitate finding them with commands like _g_r_e_p(1). Because the console port has not been initialized when these messages are issued, the PPPPaaaaggggeeee 6666 sssseeeerrrriiiiaaaallll((((7777)))) sssseeeerrrriiiiaaaallll((((7777)))) kernel is unable to display the warning on the console. Only the master IO4 provides an RS-422 port (tty4). Additional IO4 boards support three RS-232 serial ports only. To allow for future expansion, however, space was left in the serial port namespace for the additional RS-422 ports. For this reason, there is no actual device associated with tty48, tty52, and tty56. FFFFIIIILLLLEEEESSSS /dev/tty[dmf][1-4,45-56] /usr/include/sys/z8530.h /dev/MAKEDEV /var/sysgen/system SSSSEEEEEEEE AAAALLLLSSSSOOOO system(4), asoser(7), cdsio(7), keyboard(7), streamio(7), termio(7), termios(3), cserialio(7), usio(3). PPPPaaaaggggeeee 7777