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