Robust commands for timing calibration or recalibration

摘要

A memory device is placed in a mode that redefines the command set used to control the memory device. This may occur either in anticipation of the memory system falling out of calibration, or after it has already fallen out of calibration. The redefined command set is designed such that it may be reliably received by the memory device at the specified rate even if the memory system has fallen out of calibration. The redefined command set is then used to issue command(s) to recalibrate one or more communication links such that they can exchange data, commands, and/or addresses at a specified rate. After recalibration, the memory device is returned to responding to the original command set.

主权项

1. A method of operating a memory device, comprising:
receiving commands at a first link rate; receiving a first indicator to redefine a command set from a first command set to a second command set, the second command set configured to include guard bits that allow the second command set to be reliably received at the first link rate with greater timing error than the first command set is configured to be reliably received at the first link rate.