Format for Serial Data Frame With Wrap and Force Disable Messages and Special Handling for Mark 0 in With Status in
Original Publication Date: 1986-Apr-01
Included in the Prior Art Database: 2005-Mar-08
In a system for communicating between a channel processor and a device controller processor over a path that includes a parallel bus and a serial link, a serial data frame has a start field, a multi-bit command field, a multi-bit data field, and a parity field. For a data transfer, the command field of the serial frame carries one of several command codes that identify data transfer tags that are used in the parallel part of the data transfer path. For some of the messages that the channel processor and the control unit exchange before and after the data transfer, the data field carries an address byte or a status byte that is also carried on the parallel bus and the command field carries an identifying code.