Browse Prior Art Database

Node Processor Support Chip for Generic High Bandwidth Adapters

IP.com Disclosure Number: IPCOM000108653D
Original Publication Date: 1992-Jun-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 67K

Publishing Venue

IBM

Related People

Boedeker, R: AUTHOR [+4]

Abstract

This article describes the design of the 80386 Support Chip to be used in the Generic High Bandwidth Adapter (GHBA).

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Node Processor Support Chip for Generic High Bandwidth Adapters

       This article describes the design of the 80386 Support
Chip to be used in the Generic High Bandwidth Adapter (GHBA).

      The 80386 support chip (SC) controls the operation of the 80386
subsystem of the GHBA.  This subsystem functions as an independently
executing processing unit for the communication microcode needed in
the adapter.  The SC is meant to replace the many peripherals and
"glue" circuitry which are traditionally added to a microprocessor to
assist the software running on it, as well as to provide the
interface to the various devices in the subsystem and in the adapter
which can be accessed by the 80386.  This chip can be used in all
GHBA adapters using an 80386 as the node processor.  The SC is
intended to serve as the interface between the 80386 and the devices
on the Generic Adapter Bus (GAB) with which it communicates, in
addition to its subsystem control function.

      In normal operation, the SC will be the slave of the 80386 and
the master of the GAB.  As the 80386's slave, the SC will decode the
80386 address and control signals on a read or write operation and
perform the functions necessary for the access of the desired device.
These are:
      1.  Generation of the signals necessary for device access.
These include RAS, CAS, write enable, output enable, and chip
selects.
      2.  In the case of LS access, ECC generation and checking,
address multiplexing, and buffer control.
      3.  Providing control signals to the 80386, including the
re-turn of the "Ready#"...