izscd(7)                       DG/UX R4.11MU05                      izscd(7)


NAME
       izscd - Integrated Zilog Synchronous controller  (88K only)

SYNOPSIS
       izscd([controller-num[,line-num]])

DESCRIPTION
       The izscd device driver provides access to an integrated Zilog 8530
       SCC (Serial Communications Controller) device.  To configure such a
       device, you must add to the DG/UX system configuration file one or
       more device name entries of the form described in the synopsis above.
       The parameters in a device name have the following meanings:

       ·   The controller-num parameter is a hexadecimal number which
           distinguishes the various instances of the contoller that are
           available.  The default value for controller-num is 0, which is
           also the only value currently supported.

       ·   The line-num parameter is a hexadecimal number which identifies a
           particular synchronous port on the izscd device.  The value 1
           refers to port A, which is the only synchronous port on the
           device.  The default value for line-num is the special value 0,
           which identifies the izscd controller itself, distinct from any
           of the lines on it.

       The izscd driver supports the following internally generated baud
       rates:  1200, 2400, 4800 and 9600 bps.  The driver will accept any
       external clock data rate up to 9600 bps.

       The device's clock configuration must match its internal jumpers.
       The synchronous port must also be configured through the AViiON SCM.

       In conjunction with the izscd system file entries, the following
       tunable kernel parameters are used by all izscd devices configured
       into the system:

       ·   IZSCD_CLONES specifies the number of allowable clone opens for
           the clone device.  The default value is 4.

       ·   IZSCD_RXBUFF specifies the number of STREAMS buffers that will be
           pre-allocated for receiving frames.  There should always be at
           least two such buffers.  The default value is 8.

       ·   IZSCD_OVBUFF specifies the number of specifies the number of
           STREAMS buffers that will be pre-allocated to use for receiving
           frames that are larger than the configured maximum frame size.
           The default value is 3.

       ·   IZSCD_OVSIZE specifies the size in bytes of the STREAMS buffers
           that will be pre-allocated to use for receiving frames that are
           larger than the configured maximum frame size (which itself must
           not exceed 64 KB).  The default value is 1024.

       ·   IZSCD_HIWAT specifies the high water mark for streams flow
           control.  The default value is 512.

       ·   IZSCD_LOWAT specifies the low water mark for streams flow
           control.  The default value is 256.

       ·   IZSCD_MAXBAUD specifies the maximum baud rate value.  The default
           value is 9600.

FILES
       When an izscd controller is configured, it creates a character-
       special device node for each serial port, using the pathname:

           /dev/sync/line/izscd(controller-num,line-num)


       A character-special device node for the whole controller is also
       created, using the pathname:

           /dev/sync/stat/izscd(controller-num)

       This device node is a clonable Streams device node, which means that
       it can be opened multiple times in order to perform line management
       functions such as statistics manipulation and line configuration.
       I/O messages are not processed on this device.

EXAMPLES
       The following entry in a DG/UX system configuration file configures
       an izscd controller:

            izscd()



       For more information about DG/UX device configuration, refer to
       "Writing a Device Driver" in Programming in the DG/UX Kernel
       Environment.

SEE ALSO
       wanadm(1M).


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