Motorola MCF5281 ユーザーズマニュアル

15-24

MOTOROLA

 

The following assembly code initializes the SDRAM example.

Power-Up Sequence:

move.w

#0x0026, d0//Initialize DCR

move.w

d0, DCR

move.l

#0xFF880300, d0 //Initialize DACR0

move.l

d0, DACR0

move.l

#0x00740075, d0//Initialize DMR0 

move.l

d0, DMR0

Precharge Sequence:

move.l

#0xFF880308, d0//Set DACR0[IP] 

move.l

d0, DACR0

move.l

#0xBEADDEED, d0//Write and value to memory location to init. precharge

move.l

d0, 0xFF880000

Refresh Sequence:

move.l

#0xFF888300, d0//Enable refresh bit in DACR0

move.l

d0, DACR0

Mode Register Initialization Sequence:

move.l

#0x00600075, d0//Mask bit 19 of address

move.l

d0, DMR0

move.l

#0xFF888340, d0//Enable DACR0[IMRS]; DACR0[RE] remains set

move.l

d0, DACR0

move.l

#0x00000000, d0//Access SDRAM address to initialize mode register

move.l

d0, 0xFF800800