Measurement and optimization of command signal timing margins

Abstract

Techniques for training a command/address (C/A) bus, including training internal command/address (C/A) signal lines of a memory module are described. In one example, a method of training a C/A bus involves a memory controller transmitting a first command to a DRAM with parity checking enabled, the first command to include valid parity and chip select asserted. The memory controller transmits commands in cycles before and after the first command to at least one DRAM with parity checking disabled, the commands to include invalid parity and chip select asserted. In response to detecting a parity error, the memory controller modifies a timing parameter to adjust timing for the internal C/A signal lines of the memory module.