Service manual

CONFIDENTIAL – DO NOT COPY
Page 7-11
File No. SG-0198
Command Truth Table
1. Power-Up Functional Description
The following sequence is required for POWER UP.
1. Apply power and attempt to maintain CKE at a low state (all other inputs may be undefined.)
- Apply VDD before or at the same time as VDDQ.
- Apply VDDQ before or at the same time as VTT & Vref.
2. Start clock and maintain stable condition for a minimum of 200us.
3. The minimum of 200us after stable power and clock (CLK, CLK), apply NOP & take CKE high.
4. Precharge all banks.
5. Issue EMRS to enable DLL.(To issue “DLL Enable” command, provide “Low” to A0, “High” to BA0
and “Low” to all of the rest address pins, A1~A11 and BA1)
6. Issue a mode register set command for “DLL reset”. The additional 200 cycles of clock input is
required to lock the DLL. (To issue DLL reset command, provide “High” to A8 and “Low” to BA0)
7. Issue precharge commands for all banks of the device.
8. Issue 2 or more auto-refresh commands.
9. Issue a mode register set command to initialize device operation