Data Channel With Computing Engine Operated by Microcode for Different Operating Modes And Overlapped by Separate Hardware for Functions Common to All Modes
Original Publication Date: 1986-Feb-01
Included in the Prior Art Database: 2005-Mar-08
A data channel has a computing engine that executes microprograms and a control memory that can be loaded with a selected microprogram to operate the channel in one of several modes. different microprograms the channel can operate as a block, byte, or burst multiplexer, and it can operate with a central processor having a particular set of I/O instructions and a particular format for control blocks. Alternatively it can operate partly with a central processor and partly with a separate I/O processor (IOP) that handles some of the operations otherwise performed by a central processor. The channel also has hardware that performs operations that are common to all modes and/or can be overlapped with the execution of a microprogram. The channel hardware is a small processor suitably programmed for the hardware operations.