CLMPCC(4) | Device Drivers Manual (mvme68k) | CLMPCC(4)

# 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.

February 17, 2017 | NetBSD 9.5