DDR基础学习（4）--状态图
DDR -- MT46V16M16 Simplified State Diagram
图中实线粗线是自动跳转，实线细线是通过发送命令才能跳转的。
以下是具体命令定义：
Start-Up : Power on ->Precharge all banks -> MR EMR -> idle
READ : idle -> Row active -> Read -> Precharge -> idle
Write : idle -> Row active -> Write -> Precharge -> idle
Refresh : idle -> Auto Refresh-> Precharge -> idle
Self-refresh : idle -> Self refresh -> idle
2. DDR2 -- MT47H128M16 Simplified State Diagram
图中实线粗线是自动跳转，虚线细线是通过发送命令才能跳转的。
以下是具体命令定义：
Start-Up : Power on -> Initialization sequence -> IDLE
READ : idle -> Activating -> Bank Active -> Reading -> Precharging ->idle
Write : idle -> Activating -> Bank Active -> Writing -> Precharging ->idle
Refresh : idle -> Refreshing ->idle
Self-refresh : idle -> self-refresh ->idle
3. DDR3 -- MT41J128M16 Simplified State Diagram
图中虚线是自动跳转，实线是通过发送命令才能跳转的。
以下是具体命令定义：
Start-Up : Power on -> Reset Procedure -> Initialization -> ZQ Calibration -> IDLE
READ : idle -> Activating -> Bank Active -> Reading -> Precharging ->idle
Write : idle -> Activating -> Bank Active -> Writing -> Precharging ->idle
Refresh : idle -> Refreshing ->idle
Self-refresh : idle -> self-refresh ->idle
ZQ Caliration : idle -> ZQCL/ZQCS ->idle
Leveling : idle -> MRS,MPR,Write Leveling -> idle
4. DDR4 -- MT40A1G16 Simplified State Diagram
图中虚线是自动跳转，实线是通过发送命令才能跳转的。
下表是具体命令定义：
Start-Up : Power on -> Reset Procedure -> Initialization -> ZQ Calibration -> IDLE
READ : idle -> Activating -> Bank Active -> Reading -> Precharging -> idle
Write : idle -> Activating -> Bank Active -> Writing -> precharging -> idle
Refresh : idle -> Refreshing -> idle
Self-refresh : idle -> self-refresh -> idle
ZQ Caliration : idle -> ZQCL/ZQCS -> idle
Leveling : idle -> MRS,MPR,Write Leveling -> idle
