Browse Prior Art Database

One Microprocessor Checkout of Dual Microprocessor Function

IP.com Disclosure Number: IPCOM000119778D
Original Publication Date: 1991-Feb-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 1 page(s) / 47K

Publishing Venue

IBM

Related People

Batchelor, GW: AUTHOR [+4]

Abstract

This design allows card test to check out a module on a card by using an on-card microprocessor which emulates an off-card microprocessor's interface.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 76% of the total text.

One Microprocessor Checkout of Dual Microprocessor Function

      This design allows card test to check out a module on a card by
using an on-card microprocessor which emulates an off-card
microprocessor's interface.

      The on-card microprocessor emulates the off-card
microprocessor's interface by writing and reading two on-card
registers.  An on-card microprocessor register uses bits (0:7) to
emulate the address bus of the off-card microprocessor and bits
(8:15) to emulate the data bus during a write of the off-card
microprocessor.  Another on-card microprocessor register's bits
(8:15) are used to emulate the data bus during a read of the off-card
microprocessor.

      When an on-card microprocessor wants to emulate an off-card
microprocessor's interface it will set an on-card register bit to
enable card wrap mode.  Card wrap mode selects between a register and
the off-card microprocessor's interface.  During a write scenario,
bits (0:7) of the on-card microprocessor register will be used as the
address bus sent to the write decode bits.  Bits (8:15) of the
on-card microprocessor register will be used as the data bus sent to
update the off-card microprocessor's registers. During a read
scenario, the address bus sent to the read decode is again bits (0:7)
of that register.  Another on-card microprocessor register's bits
(8:15) will be read to obtain the contents of the read data bus
during card wrap mode.

      This invention has also been used s...