MCF548x Reference Manual, Rev. 3
18-34 Freescale Semiconductor

18.8.12 Initialization Code

The following assembly code initializes the DDR SDRAM using the register values determined above.
Basic Configuration and Initialization:
move.l #0x000002AA, d0//Initialize SDRAMDS
move.l d0, SDRAMDS
move.l #0x00000019, d0//Initialize SDCS0
move.l d0, CS0CFG
move.l #0x73622830, d0//Initialize SDCFG1
move.l d0, SDCFG1
move.l #0x46770000, d0//Initialize SDCFG2
move.l d0, SDCFG2
Precharge Sequence and enable write to SDMR:
move.l #0xE10D0002, d0//Initialize SDCR, send PALL, enable SDMR
move.l d0, SDCR
Write Extended Mode Register:
move.l #0x40010000, d0//Write LEMR to enable DLL
move.l d0, SDMR
Write Mode Register and Reset DLL:
move.l #0x048D0000, d0//Write LMR and reset DLL
move.l d0, SDMR
Precharge Sequence:
move.l #0xE10D0002, d0//Send PALL
move.l d0, SDCR
Refresh Sequence:
move.l #0xE10D0004, d0//Send first REF command
move.l d0, SDCR
move.l #0xE10D0004, d0//Send second REF command
move.l d0, SDCR
Write Mode Register and Clear Reset DLL:
15–12 0000 Reserved. Should be cleared.
11–8 DQS_OE 1111 0xF enables drive for all SDDQS pins.
7–5 000 Reserved. Should be cleared.
4 BUFF 0 0 indicates that a buffered memory module is not being used.
3 0 Reserved. Should be cleared.
2 IREF 0 Initiate a REF command.
1 IPALL 0 Do not initiate a PALL command.
0 0 Reserved. Should be cleared.
Table 18-25. SDCR + REF Field Descriptions (Continued)
Bits Name Setting Description