QUALCOMM Incorporated
SYSTEM AND METHOD FOR COMPENSATING FOR SDRAM SIGNAL TIMING DRIFT THROUGH PERIODIC WRITE TRAINING

Abstract:

Signal timing drift in a synchronous dynamic random access memory (SDRAM) system may be compensated for by performing write signal timing training using a multi-purpose command (MPC) first-in-first-out (FIFO) write and MPC FIFO read at periodic intervals interspersed with mission-mode SDRAM traffic. The test result samples obtained from the write signal timing training may be analyzed independently of mission-mode SDRAM traffic. The mission-mode timing of the SDRAM data bit signals relative to the SDRAM write clock signal may be adjusted based on the analysis.