SCC(4)                OpenBSD Programmer's Manual (Alpha)               SCC(4)

NAME
     scc - Zilog serial communications interface

SYNOPSIS
     scc0 at ioasic?
     scc1 at ioasic?

DESCRIPTION
     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
     /dev/ttyB0

     /dev/ttyB1

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

SEE ALSO
     intro(4), tty(4)

HISTORY
     The scc driver first appeared in 4.4BSD.

BUGS
     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 sup-
     ported.

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

OpenBSD 4.7                      May 31, 2007                                1
