FreeBSD Man Pages

digi(4)

NAME

     digi -- DigiBoard intelligent serial cards driver

SYNOPSIS

     device digi

     This man page was originally written for the dgb driver, and should
     likely be gone over with a fine tooth comb to reflect differences with
     the digi driver.

     When not defined the number is computed:

	 default NDGBPORTS = number_of_described_DigiBoard_cards * 16

     If it is less than the actual number of ports the system will be able to
     use only the first NDGBPORTS ports.  If it is greater then all ports will
     be usable but some memory will be wasted.

     Meaning of flags:
     0x0001  use alternate pinout (exchange DCD and DSR lines)
     0x0002  don't use 8K window mode of PC/Xe

     Device numbering:
     0bCCmmmmmmmmOLIPPPPP
       CCard number
	 mmmmmmmmajor number
		 callOut
		  Lock
		   Initial
		    PPPPPort number

DESCRIPTION

     The digi driver provides support for DigiBoard PC/Xe and PC/Xi series
     intelligent serial multiport cards with asynchronous interfaces based on
     the EIA RS-232C (CCITT V.24) standard.

     Input and output for each line may set to one of following baud rates;
     50, 75, 110, 134.5, 150, 300, 600, 1200, 1800, 2400, 4800, 9600, 19200,
     38400, 57600, or for newer versions of cards 115200.

     The driver doesn't use any interrupts, it is ``polling-based''.  This
     means that it uses clock interrupts instead of interrupts generated by
     DigiBoard cards and checks the state of cards 25 times per second.  This
     is practical because the DigiBoard cards have large input and output
     buffers (more than 1Kbyte per port) and hardware that allows efficiently
     finding the port that needs attention.  The only problem seen with this
     policy is slower SLIP and PPP response.

     Each line in the kernel configuration file describes one card, not one
     port as in the sio(4) driver.

     The flags keyword may be used on each ``device dgb'' line in the kernel
     configuration file to change the pinout of the interface or to use new
     PC/Xe cards which can work with an 8K memory window in compatibility mode
     (with a 64K memory window).  Note that using 8K memory window doesn't
     mean shorter input/output buffers, it means only that all buffers will be
     mapped to the same memory address and switched as needed.

     The same range of memory addresses may be used for all the DigiBoards
     installed (but not for any other card or real memory).  DigiBoards with a
     large amount of memory (256K or 512K and perhaps even 128K) must be
     mapped to memory addresses outside of the first megabyte.	If the com-
     puter has more than 15 megabytes of memory then there is no free address
     space outside of the first megabyte where such DigiBoards can be mapped.
     In this case you may need to reduce the amount of memory in the computer.
     But many machines provide a better solution.  They have the ability to
     ``turn off'' the memory in the 16th megabyte (addresses 0xF00000 -
     0xFFFFFF) using the BIOS setup.  Then the DigiBoard's address space can
     be set to this ``hole''.

     Serial ports controlled by the digi driver can be used for both
     ``callin'' and ``callout''.  For each port there is a callin device and a
     callout device.  The minor number of the callout device is 128 higher
     than that of the corresponding callin port.  The callin device is general
     purpose.  Processes opening it normally wait for carrier and for the
     callout device to become inactive.  The callout device is used to steal
     the port from processes waiting for carrier on the callin device.	Pro-
     cesses opening it do not wait for carrier and put any processes waiting
     for carrier on the callin device into a deeper sleep so that they do not
     conflict with the callout session.  The callout device is abused for han-
     dling programs that are supposed to work on general ports and need to
     open the port without waiting but are too stupid to do so.

     The digi driver also supports an initial-state and a lock-state control
     device for each of the callin and the callout ``data'' devices.  The
     minor number of the initial-state device is 32 higher than that of the
     corresponding data device.  The minor number of the lock-state device is
     64 higher than that of the corresponding data device.  The termios set-
     tings of a data device are copied from those of the corresponding ini-
     tial-state device on first opens and are not inherited from previous
     opens.  Use stty(1) in the normal way on the initial-state devices to
     program initial termios states suitable for your setup.

     The lock termios state acts as flags to disable changing the termios
     state.  E.g., to lock a flag variable such as CRTSCTS, use ``stty
     crtscts'' on the lock-state device.  Speeds and special characters may be
     locked by setting the corresponding value in the lock-state device to any
     nonzero value.

     Correct programs talking to correctly wired external devices work with
     almost arbitrary initial states and no locking, but other setups may ben-
     efit from changing some of the default initial state and locking the
     state.  In particular, the initial states for non (POSIX) standard flags
     should be set to suit the devices attached and may need to be locked to
     prevent buggy programs from changing them.  E.g., CRTSCTS should be
     locked on for devices that support RTS/CTS handshaking at all times and
     off for devices that don't support it at all.  CLOCAL should be locked on
     for devices that don't support carrier.  HUPCL may be locked off if you
     don't want to hang up for some reason.  In general, very bad things hap-
     pen if something is locked to the wrong state, and things should not be
     locked for devices that support more than one setting.  The CLOCAL flag
     on callin ports should be locked off for logins to avoid certain security
     holes, but this needs to be done by getty if the callin port is used for
     anything else.


     /etc/rc.serial  examples of setting the initial-state and lock-state
		     devices

     The first question mark in these device names is short for the card num-
     ber (a decimal number between 0 and 65535 inclusive).  The second ques-
     tion mark is short for the port number (a letter in the range [0-9a-v]).

DIAGNOSTICS

     You may enable extended diagnostics by defining DEBUG at the start of the
     source file dgb.c.

     dgbX: warning: address N truncated to M  The memory address for the
     PC/Xe's 8K window is misaligned (it should be on an 8K boundary) or out-
     side of the first megabyte.

     dgbX: 1st reset failed  Problems with accessing I/O port of the card,
     probably the wrong port value is specified in the kernel config file.

     dgbX: 2nd reset failed  Problems with hardware.

     dgbX: N[st,nd,rd,th] memory test failed  Problems with accessing the mem-
     ory of the card, probably the wrong iomem value is specified in the ker-
     nel config file.

     dgbX: BIOS start failed  Problems with starting the on-board BIOS.  Prob-
     ably the memory addresses of the DigiBoard overlap with some other device
     or with RAM.

     dgbX: BIOS download failed  Problems with the on-board BIOS.  Probably
     the memory addresses of the DigiBoard overlap with some other device or
     with RAM.

     dgbX: FEP code download failed  Problems with downloading of the Front-
     End Processor's micro-OS.	Probably the memory addresses of the DigiBoard
     overlap with some other device or with RAM.

     dgbX: FEP/OS start failed	Problems with starting of the Front-End Pro-
     cessor's micro-OS.  Probably the memory addresses of the DigiBoard over-
     lap with some other device or with RAM.

     dgbX: too many ports  This DigiBoard reports that it has more than 32
     ports.  Perhaps a hardware problem or the memory addresses of the Digi-
     Board overlap with some other device or with RAM.

     dgbX: only N ports are usable  The NDGBPORTS parameter is too small and
     there is only enough space allocated for N ports on this card.

     dgbX: port Y is broken  The on-board diagnostic has reported that the
     specified port has hardware problems.

     dgbX: polling of disabled board stopped  Internal problems in the polling
     logic of driver.

     dgbX: event queue's head or tail is wrong!  Internal problems in the
     driver or hardware.

     dgbX: port Y: got event on nonexisting port  Some status changed on a

     dgbX: port Y: FEP command on disabled port  Internal problems in driver.

     dgbX: port Y: timeout on FEP command  Problems in hardware.

SEE ALSO

     stty(1), termios(4), tty(4), comcontrol(8)

HISTORY

     The digi driver is derived from the sio(4) driver and the DigiBoard
     driver from Linux and is currently under development.

BUGS

     The implementation of sending BREAK is broken.  BREAK of fixed length of
     1/4 s is sent anyway.

     There was a bug in implementation of select(2).  It is fixed now but not
     widely tested yet.

     There is no ditty command.  Most of its functions (alternate pinout,
     speed up to 115200 baud, etc.) are implemented in the driver itself.
     Some other functions are missing.

FreeBSD 5.4		       December 7, 2003 		   FreeBSD 5.4

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