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回复 #1 conke 的帖子
以下是我初始化内存的代码,但是测试好像读写不了内存
*************************************
@InitMem:
ldr r0, =AT91SAM926X_PA_MATRIX
ldr r1, =((1 << 16) | 2)
str r1, [r0, #MATRIX_EBI0CSA]
ldr r0, =AT91SAM926X_PA_PIOD
ldr r1, =0xffff0000
str r1, [r0, #PIO_ASR]
ldr r0, =AT91SAM926X_PA_SDRAMC
ldr r1, =0x85227279
str r1, [r0, #SDRAMC_CR]
mov r1, #0
str r1, [r0, #SDRAMC_MDR]
@delay 200 * 1000 ns = 40000 pck
mov r2, #0x4f00
loop5:
sub r2, r2, #1
cmp r2, #1
bne loop5
mov r1, #1
str r1, [r0, #SDRAMC_MR]
ldr r3, =SDRAM_BASE
str r1, [r3]
mov r1, #2
str r1, [r0, #SDRAMC_MR]
str r1, [r3]
mov r2, #8
loop6:
mov r1, #4
str r1, [r0, #SDRAMC_MR]
str r1, [r3]
sub r2, r2, #1
bge loop6
mov r1, #3
str r1, [r0, #SDRAMC_MR]
str r1, [r3]
mov r1, #0
str r1, [r0, #SDRAMC_MR]
str r1, [r3]
ldr r1, =1562
str r1, [r0, #SDRAMC_TR]
@test the mem
mov r1, #3
str r1, [r3]
ldr r2, [r3]
cmp r2, r1
bne hang
OnLed:
ldr r0, =AT91SAM926X_PA_PIOC
@ ds1 & pc29
mov r1, #0x20000000
str r1, [r0,#PIO_PER]
str r1, [r0,#PIO_OER]
str r1, [r0,#PIO_CODR]
hang:
b hang |
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