RH(4) BSD Programmer's Manual RH(4)NAMErh - SDL Communications RISCom/H2 dual high-speed synchronous interface
SYNOPSIS
rh0 at isa? port 0x240 drq 6
DESCRIPTION
The rh interface provides two point-to-point bit-synchronous serial con-
nections with speeds up to 4 Mb/s using HDLC frame format. It uses a
switch-selectable block of 8 I/O ports in the range 0x200 through 0x3f0.
The block must be aligned on a 16 port boundary. The jumper-selectable
interrupt level is detected at autoconfiguration time or alternatively
can be specified in the system configuration file. Supported IRQs are:
3, 4, 5, 6, 10, 11, 12 and 15. No I/O memory is used. A 16-bit DMA
channel should be specified in the kernel configuration file and selected
by on-board jumpers; supported DRQs are 5, 6 and 7. The RISCom/H2 board
should be installed in a 16-bit slot.
Supported synchronous serial encapsulation protocols are described in
p2p(4).
The interface flag IFF_LINK0 turns on the internal clock, settable via
the link0 option of ifconfig(8).
DIAGNOSTICS
The following diagnostics may be printed during autoconfiguration:
rh%d: illegal base address %x
Invalid port specification in kernel config file.
rh%d: illegal drq %d
Invalid DRQ specification in kernel config file.
rh%d: illegal IRQ %d
Invalid IRQ specification in kernel config file.
rh%d: no memory for the channel 1 data
The attach routine cannot allocate memory for the channel 1. Should nev-
er happen.
SEE ALSOintro(4), inet(4), p2p(4), ifconfig(8)BUGS
The RISCom/H2 board uses cascade DMA mode which is known not to work on
some motherboards. Make sure your motherboard works correctly with the
RISCom/H2 using the manufacturer-supplied test program.
The maximal transmission speed may vary depending on the processor speed
and ISA bus timing parameters.
BSDI BSD/OS March 1, 1993 1
