ASY(4) —
NAME
asy − multi-port asynchronous communications RS232C interface
SYNOPSIS
For the IBM RT PC:
device asy0 at iocc0 csr 0xf0001230 flags 0x01
device asy1 at iocc0 csr 0xf0002230 flags 0x0f
device asy2 at iocc0 csr 0xf0003230 flags 0x0f
device asy3 at iocc0 csr 0xf0004230 flags 0x0f
device asy4 at iocc0 csr 0xf00003f8 flags 0x00
device asy5 at iocc0 csr 0xf00002f8 flags 0x00
For the IBM 6152 Academic System:
device asy4 at iocc csr 0x000003f8 flags 0xff priority 4
DESCRIPTION
The IBM RT PC multi-port asynchronous communications adapter card provides four serial RS232C ports, asy0 through asy3.
The IBM RT PC can support up to four adapters. Four separate I/O address ranges (0xf0001230, 0xf0002230, 0xf0003230 and 0xf0004230) and three separate interrupt levels (IRQ9, IRQ10, IRQ11) are reserved for the multiport adapters. Two adapters may share the same interrupt level, but not the same I/O address range.
On the IBM RT PC, this driver also supports the serial line of up to two PC/AT serial/parallel adapters. These adapters must be specified as asy4 and/or asy5 in the config(8) file even if you do not have any multi-port adapters configured.
On the IBM 6152 Academic System, this driver supports the planar serial port on the PS/2. This must be specified as asy4 in the config(8) file.
The adapter supports only asynchronous communications, and is fully programmable. Each port behaves as described in tty(4) and may be set to run at any of 16 speeds; see tty(4) for the encoding.
Bit i of flags may be set to 1 to specify that the ith port should be treated as having carrier initially present. For example, specifying “flags 0x01” in the configuration entry for asy0 causes only the line tty00 to be treated in this way.
FILES
For the IBM RT PC:
/dev/tty{00,01,...,15} for multi-port cards
/dev/ttyc[01] for PC/AT serial/parallel adapters
/dev/ttyd[0-9a-f](dialups)
For the IBM 6152 Academic System:
/dev/ttyc0 for PS/2 planar serial port
SEE ALSO
DIAGNOSTICS
asy%d: overrun error. Data has been lost because characters are arriving at the adapter faster than the driver can read them.
NOTES
This driver should also support the IBM RT PC RS422A protocol in so far as the programming interface is the same. However, this has not been tested.
Both the buffered and unbuffered four port adapter cards are supported by the asy interface. Higher transmission speeds can be obtained using the buffered card. Note that the actual transmission speed obtained may also depend on what other hardware is being used on the machine.
PRPQs 5799-WZQ/5799-PFF: IBM/4.3 — Sept 1988