US 2007/0183231 A1 · Method of operating a memory system

Abstract

The memory system has a current source architecture that has a separate current source for each group in a block of memory. When a leaky cell is detected, a fuse between the current source and the leaky group of cells is blown and a spare group of memory is substituted for the leaky group of memory. The current source architecture can be used in a current source test mode or in a current force test mode. The current source test mode detects if there is a leaky group of memory. In the current force test mode, the architecture determines the amount of current required by each group of memory to retain data. This information is then used to apply the required amount of current to each group of memory for data retention.

Claims20

Dependent claims

A method of operating a memory system, comprising the steps of:

a) providing a plurality of current source circuits for a plurality of memory groups;
b) providing a fuse between each of the plurality of current source circuits and the plurality of memory groups forming a block of memory.

Dependencies are inferred from the claim text.

Facts

Application

11/701,926Filed 2 Feb 2007

Priority

IN 167/CHE/20062 Feb 2006

Published

9 Aug 2007

Term ends

Not estimatedThe source records don’t support an estimate.

Classification6 codes

G11C 29/50
Detection or location of defective memory elements , e.g. cell constructio details, timing of test signals: marginal testing, e.g. race, voltage…
G11C 29/50016
Marginal testing, e.g. race, voltage or current testing: of retention
G11C 29/83
Using programmable devices: with reduced power consumption
G11C 11/41
Using transistors: forming static cells with positive feedback, i.e. cells not needing refreshing or charge regeneration, e.g. bistable…

Method of operating a memory system

Life of this patent

Method of operating a memory system

Life of this patent

Abstract

Claims20