NAME    [Toc]    [Back]

     scc - Zilog serial communications interface

SYNOPSIS    [Toc]    [Back]

     scc0 at ioasic? offset ?
     scc1 at ioasic? offset ?

DESCRIPTION    [Toc]    [Back]

     The scc driver provides support for the  Zilog  8530  Serial
Communications
     Controller  (SCC)  via  the IOCTL asic on TURBOchannel-based
alphas (the DEC
     3000 series).  Each scc device has two serial ports.

     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, or 57600.  Speeds up to 230400 are supported  by  the
chip and the
     motherboard,  but speeds higher than 57600 do not work reliably without an
     external clock signal.

FILES    [Toc]    [Back]

     /dev/ttyB0

     /dev/ttyB1

     The mapping from units to  serial-hardware  outlets  is  idiosyncratic.

SEE ALSO    [Toc]    [Back]

     intro(4), tty(4)

HISTORY    [Toc]    [Back]

     The scc driver first appeared in 4.4BSD.

BUGS    [Toc]    [Back]

     The  IOCTL  asic  provides internal DMA channels that can be
programmed to
     transfer up to 4096 bytes of data into, or out,  of  an  SCC
without further
     software  intervention.   This  feature of the ioctl asic is
not yet supported.


     The mapping from device-special files (major and minor  number) to chip
     and port is arguably backwards.

OpenBSD      3.6                           March      7,     1998