DDR2DDR2 SDRAM Device Operation & Timing Diagram 1 DDR2 Device Operations & Timing Diagram Contents 1. Functioanal Description 1.1 Simplified State Diagram 1.2 Basic Function & Operation of DDR2 SDRAM 1.2.1 Power up and Initialization 1.2.2 Programming the Mode and Extended Mode Registers 1.2.2.1 DDR2 SDRAM Mode Register Set(MRS) 1.2.2.2 DDR2 SDRAM Extended Mode Register Set 1.2.2.3 Off-Chip Driver(OCD) Impedance Adjustment 1.2.2.4 ODT(On Die Termination) 1.3 Bank Activate Command 1.4 Read and Write Command 1.4.1 Posted CAS 1.4.2 Burst Mode Operation 1.4.3 Burst Read Command 1.4.4 Burst Write Operation 1.4.5 Write Data Mask 1.5 Precharge Operation 1.6 Auto Precharge Operation 1.6 Refresh Commands 1.7.1 Auto Refresh Command 1.7.2 Self Refresh Command 1.8 Power Down 1.9 Asynchronous CKE Low ……