Browse Prior Art Database

Simultaneous Bidirectional Chip to Chip Communication

IP.com Disclosure Number: IPCOM000117298D
Original Publication Date: 1996-Jan-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 59K

Publishing Venue

IBM

Related People

Cao, TA: AUTHOR [+5]

Abstract

Disclosed is a method to achieve higher data rate transfer between CMOS Microprocessor chips so that the system performance is not limited by the rate of transfer between chips. All signal I/O connection points to the chip and module are assumed to have been used up.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 55% of the total text.

Simultaneous Bidirectional Chip to Chip Communication

      Disclosed is a method to achieve higher data rate transfer
between CMOS Microprocessor chips so that the system performance is
not limited by the rate of transfer between chips.  All signal I/O
connection points to the chip and module are assumed to have been
used up.

      This proposal uses a Simultaneous Bidirectional Chip to Chip
driver circuit that effectively doubles the data rates for many of
the signal pins found on a microprocessor and its attached support
chip(s).

The schematic of the disclosure is shown in the Figure.

      Two chips are shown.  Driver A on chip 1 sends signals to
receiver A on chip 2.  Similarly, driver B on chip 2 sends signals to
receiver B on chip 1.

      The driver A signal is not received by receiver B and the
driver B signal is not received by receiver A.

      Signals from driver A are transmitted at the same time as
signals from driver B, hence the name Simultaneous Bidirectional.

      Driver output impedances, resistor values Ra and Rb are
arranged such that the signal on the transmission line has the
following relative levels.  Reflections are ignored here,
particularly for short distance.

      The signal received at chip 2 is fed into a differential sense
circuit that also has a reference voltage input, VREF = 1.25v.
Looking at the above waveform one can see that receiver A will switch
when the on input signal from the line crosses the...