June 5, 1993 PCL 4 vax

### NAME

pcl - DEC CSS PCL-11 B Network Interface

### SYNOPSIS

pcl0 at uba? csr 164200 vector pclxint pclrint

### DESCRIPTION

NOTE: This driver has not been ported from 4.4BSD yet.

The pcl device provides an IP-only interface to the DEC CSS PCL-11 time division multiplexed network bus. The controller itself is not accessible to users.

The host's address is specified with the ```SIOCSIFADDR` ioctl(2). The interface will not transmit or receive any data before its address is defined.

As the PCL-11 hardware is only capable of having 15 interfaces per network, a single-byte host-on-network number is used, with range [1..15] to match the TDM bus addresses of the interfaces.

The interface currently only supports the Internet protocol family and only provides ``natural'' (header) encapsulation.

### DIAGNOSTICS

pcl%d: can't init.
  Insufficient UNIBUS resources existed to initialize the device. This is likely to occur when the device is run on a buffered data path on an 11/750 and other network interfaces are also configured to use buffered data paths, or when it is configured to use buffered data paths on an 11/730 (which has none).

pcl%d: can't handle af%d.
  The interface was handed a message with addresses formatted in an unsuitable address family; the packet was dropped.

pcl%d: stray xmit interrupt.
  An interrupt occurred when no output had previously been started.

pcl%d: master.
  The TDM bus had no station providing ``bus master'' timing signals, so this interface has assumed the ``master'' role. This message should only appear at most once per UNIBUS INIT on a single system. Unless there is a hardware failure, only one station may be master at a time.

pcl%d: send error, tcr=%b, tsr=%b.
  The device indicated a problem sending data on output. If a ``receiver offline'' error is detected, it is not normally logged unless the option ```PCL_TESTING` has been selected, as this causes a lot of console chatter when sending to a down machine. However, this option is quite useful when debugging problems with the PCL interfaces.

pcl%d: rcv error, rcr=%b rsr=%b.
  The device indicated a problem receiving data on input.

pcl%d: bad len=%d.
  An input operation resulted in a data transfer of less than 0 or more than 1008 bytes of data into memory (according to the word count register). This should never happen as the maximum size of a PCL message has been agreed upon to be 1008 bytes (same as ARPANET message).

### SEE ALSO

inet(4), intro(4)

### HISTORY

The pcl interface appeared in 4.2BSD.