NAME
clmpcc —
Cirrus Logic CD2400/CD2401
serial communications controller
SYNOPSIS
clmpcc0 at pcctwo? ipl 4
DESCRIPTION
The
clmpcc driver provides support for the Cirrus Logic CD2401
Multi-protocol Communications Controller found on Motorola MVME167 and MVME177
single-board computers.
The chip integrates four serial channels in one package, with each channel being
completely independent and capable of running in Async (with optional DMA
control), Bisync, HDLC/SDLC and X.21 modes. Each channel has 32 bytes of FIFO,
split into 16 bytes for the Tx side and 16 bytes for the Rx side.
At the present time, the
clmpcc driver supports the non-DMA
Async mode of operation, using the channel FIFOs to maximize throughput with
minimal interrupt overhead.
The Motorola MVME1x7 boards provide a 20MHz master clock to the device, which
allows the Tx and Rx side to be independently set to any baud rate in the
range 50 to 57600. The device should be capable of running at a baud rate of
115200, however it is not a rate documented in the device's datasheet for
Async. mode so is not recommended.
FILES
-
-
- /dev/console
-
- /dev/ttyC1
-
- /dev/ttyC2
-
- /dev/ttyC3
-
DIAGNOSTICS
- clmpcc%d: channel %d command timeout
(idle)
- The chip failed to acknowledge a command sent to the
specified channel.
- clmpcc%d: Failed to reset chip
- The clmpcc driver was unable to
determine if the chip completed its RESET processing.
SEE ALSO
mvme68k/pcctwo(4),
tty(4)
HISTORY
The
clmpcc driver first appeared in
NetBSD
1.4 and is currently under development.
BUGS
The hardware flow control features of the chip are not yet fully
supported.