Regulation of memory IO timing using programmatic control over memory device IO timing

Patent metadata

Field	Value
Publication number	US-8930740-B2
Application number	US-94775810-A
Country	US
Kind code	B2
Filing date	Nov 16, 2010
Priority date	Feb 23, 2010
Publication date	Jan 6, 2015
Grant date	Jan 6, 2015

Abstract

This disclosure provides for adjustment of memory IO timing using a voltage controlled oscillator (VCO) and a register that generates a VCO control voltage directly used to vary memory IO timing. The register may be externally programmable by a controller and may be located on a memory device (IC, module or other device) or on an external voltage generator, which then provides an adjustable voltage to the memory device. This structure may be used to adjust memory timing so as to achieve a minimum target bitrate and thus minimize frequency of operation to minimize power. In one embodiment, each of several memory devices may be independently adjusted in this way to achieve a mesochronous memory system; in another embodiment, memory devices may be have their timing adjusted in parallel, with all memory devices equal to or greater than a target bitrate. Teachings presented herein provide a way to relax overdesign requirements and “tune” fast-fast and slow-slow devices to effectively operate as typical devices.

First claim

We claim:

1. A memory device, comprising:
a memory core;
a programmable oscillator that generates a timing signal based on information stored in an externally-programmable register; and
a data interface for timing exchange of data with an external data channel based on the timing signal;
where the data interface includes a transmitter to time the transmission of read data to a memory controller according to a transmit clock signal, the transmit clock signal generated using t…

Assignees

• Zerbe Jared L
• Best Scott C
• Leibowitz Brian L
• Rambus Inc

Inventors

• Zerbe Jared L
• Best Scott C
• Leibowitz Brian L

Classifications

• G06F1/32

  Physics · mapped topic

• G06F13/1689

  Physics · mapped topic

• G06F1/08 Primary

  Physics · mapped topic