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CY(4)                  FreeBSD Kernel Interfaces Manual                  CY(4)

     cy -- Cyclades Cyclom-Y serial driver

     For one ISA card:
           device cy

           In /boot/device.hints:

     For two ISA cards:
           device cy

           In /boot/device.hints:

     For PCI cards:
           device cy
           options CY_PCI_FASTINTR

           No lines are required in /boot/device.hints for PCI cards.

     Minor numbering:
             MMMMMMMMMMMMMMMM           MMMMMMinor

     The cy driver provides support for Cirrus Logic CD1400-based EIA RS-232C
     (CCITT V.24) communications interfaces (ports) on Cyclades Cyclom-Y
     boards.  Each CD1400 provides 4 ports.  Cyclom-Y boards with various num-
     bers of CD1400's are available.  This driver supports up to 8 CD1400's
     (32 ports) per board.

     Input and output for each line may set independently to the following
     speeds: 50, 75, 110, 134.5, 150, 300, 600, 1200, 1800, 2400, 4800, 9600,
     19200, 38400, 57600, or 115200 bps.  Other speeds of up to 150000 are
     supported by the termios interface but not by the sgttyb compatibility
     interface.  The CD1400 is not fast enough to handle speeds above 115200
     bps effectively.  It can transmit on a single line at slightly more than
     115200 bps, but when 4 lines are active in both directions its limit is
     about 90000 bps on each line.

     Serial ports controlled by the cy 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.  Processes 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 handling 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 cy 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 corre-
     sponding data device.  The minor number of the lock-state device is 64
     higher than that of the corresponding data device.  The termios settings
     of a data device are copied from those of the corresponding initial-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

     Correct programs talking to correctly wired external devices work with
     almost arbitrary initial states and almost no locking, but other setups
     may benefit 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 do not support it at all.  CLOCAL should
     be locked on for devices that do not support carrier.  HUPCL may be
     locked off if you do not want to hang up for some reason.  In general,
     very bad things happen if something is locked to the wrong state, and
     things should not be locked for devices that support more than one set-
     ting.  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.

   Kernel Configuration Options
     The CY_PCI_FASTINTR option should be used to avoid suboptimal interrupt
     handling for PCI Cyclades boards.  The PCI BIOS must be configured with
     the cy interrupt not shared with any other active device for this option
     to work.  This option is not the default because it is currently harmful
     in certain cases where it does not work.

     /dev/ttyc??   for callin ports
     /dev/ttylc??  corresponding callin initial-state and lock-state devices

     /dev/cuac??   for callout ports
     /dev/cualc??  corresponding callout initial-state and lock-state devices

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

     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]).

     cy%d: silo overflow.  Problem in the interrupt handler.

     cy%d: interrupt-level buffer overflow.  Problem in the bottom half of the

     cy%d: tty-level buffer overflow.  Problem in the application.  Input has
     arrived faster than the given module could process it and some has been

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

     The cy driver is derived from the sio driver and the NetBSD cy driver and
     is currently under development.

     Serial consoles are not implemented.

FreeBSD 6.2                      May 24, 2004                      FreeBSD 6.2


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