NEC µPD72257 Preliminary User's Manual page 296

Chapter 9
Figure 9-2
SDRAM mode
initialization
296
MEMSTMG1R.
TINIT
MEMSTMG0R.
TRP
MEMSTMG0R.
TRCAR
SDRAM power-on command sequence
The Memory Controller automatically sets the SDRAM devices' mode registers
during the power-up initialization.
If the SDRAM mode registers shall be rewritten during normal operation, set
MEMSCTRL.SDRMODE = 1.
After the Memory Controller finishes the SDRAM devices' mode register setting,
it clears MEMSCTRL.SDRMODE to 0.
Following parameters are written to the SDRAM devices' mode register:
Preliminary User's Manual S19203EE1V3UM00
External Memory Interface Controller
Apply power
and start clock
NOP
NOP
NOP
Precharge all banks
NOP
NOP
Auto-refresh
NOP
NOP
Set SDRAM mode register
NOP
NOP
NOP
Ready for data transfer
MEMSTMG1R.
INITREF