Browse Prior Art Database

Soft Error Protection for Dynamic Complementary Metal Oxide Semiconductor Circuitry

IP.com Disclosure Number: IPCOM000118795D
Original Publication Date: 1997-Jul-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Chu, S: AUTHOR [+4]

Abstract

Disclosed is a technique to enhance dynamic Complementary Metal Oxide Semiconductor (CMOS) circuits to reduce the probability of a logic failure caused by alpha particles hitting a stored node in high impedance state.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 65% of the total text.

Soft Error Protection for Dynamic Complementary Metal Oxide Semiconductor
Circuitry

      Disclosed is a technique to enhance dynamic Complementary Metal
Oxide Semiconductor (CMOS) circuits to reduce the probability of a
logic failure caused by alpha particles hitting a stored node in high
impedance state.

      Alpha particles pose a well-known problem to the integrity of
correct logical operation of dynamic memory storage cells.  With the
scaling down of Very Large Scale Integration (VLSI) circuits, similar
problems can cause dynamic logic circuits to malfunction.

      Typically, in dynamic circuits, the internal node is precharged
high during the precharge phase of the clock.  During the evaluate
phase, the internal node is in a high impedance state held high by
the charged parasitic capacitance of that node.  In other words,
there is no active device holding the node high.  During this time,
an alpha particle hit could drain the charge at the internal node
enough to falsely switch the output, and the circuit will not be able
to recover  till the next precharge phase following the alpha
particle hit.

      The disclosed technique modifies the clock to the precharge
device such that the precharge phase of the circuit is extended.
This can be done in a number of ways, one of which is as follows.
The last  arriving evaluate signal can be used to turn off the
precharge phase which would ensure the turn on of the precharge
device for a much longer ...