Samsung S5PC110 Manual page 548

S5PC110_UM
17. Issue a MRS command using the DirectCmd register to reset memory device and program the operating
parameters.
18. Wait for minimum 1us.
19. Issue a MRR command using the DirectCmd register to poll the DAI bit of the MRStatus register to know
whether Device Auto-Initialization is completed or not.
20. If there are two external memory chips, perform steps 15 ~ 19 for chip1 memory device.
21. Set the ConControl to turn on an auto refresh counter.
22. If power down modes is required, set the MemControl registers.
1.2.1.3 DDR2
Initialization sequence for DDR2 memory type:
1. To provide stable power for controller and memory device, the controller must assert and hold CKE to a logic
low level. Then apply stable clock. Note: XDDR2SEL should be High level to hold CKE to low.
2. Set the PhyControl0.ctrl_start_point and PhyControl0.ctrl_inc bit-fields to correct value according to clock
frequency. Set the PhyControl0.ctrl_dll_on bit-field to '1' to turn on the PHY DLL.
3. DQS Cleaning: Set the PhyControl1.ctrl_shiftc and PhyControl1.ctrl_offsetc bit-fields to correct value
according to clock frequency and memory tAC parameters.
4. Set the PhyControl0.ctrl_start bit-field to '1'.
5. Set the ConControl. At this moment, an auto refresh counter should be off.
6. Set the MemControl. At this moment, all power down modes should be off.
7. Set the MemConfig0 register. If there are two external memory chips, set the MemConfig1 register.
8. Set the PrechConfig and PwrdnConfig registers.
9. Set the TimingAref, TimingRow, TimingData and TimingPower registers according to memory AC
parameters.
10. If QoS scheme is required, set the QosControl0~15 and QosConfig0~15 registers.
11. Wait for the PhyStatus0.ctrl_locked bit-fields to change to '1'. Check whether PHY DLL is locked.
12. PHY DLL compensates the changes of delay amount caused by Process, Voltage and Temperature (PVT)
variation during memory operation. Therefore, PHY DLL should not be off for reliable operation. It can be off
except runs at low frequency. If off mode is used, set the PhyControl0.ctrl_force bit-field to correct value
according to the PhyStatus0.ctrl_lock_value[9:2] bit-field to fix delay amount. Clear the
PhyControl0.ctrl_dll_on bit-field to turn off PHY DLL.
13. Confirm whether stable clock is issued minimum 200us after power on
14. Issue a NOP command using the DirectCmd register to assert and to hold CKE to a logic high level.
1 DRAM CONTROLLER
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