DCM(4) | Device Drivers Manual (hp300) | DCM(4) |
dcm
—
dcm* at dio? scode ? flags 0xe
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.
Flags is usually specified as 0xe since 3 of
the 4 ports (1-3) do not support modem control and should be treated as
hard-wired with carrier always present. If port 0 does not have the need for
modem control then flags can be specified as
‘0xf
’.
Each port on the 98642A has a 128 byte input silo and a 16 byte output silo. Interrupts happen on a per character basis unless the interrupt rate for the card reaches 70 interrupts per second at which time the driver changes to a 16.7ms (60 interrupts per second) polling scheme until the interrupt rate drops.
February 17, 2017 | NetBSD 9.4 |