微處理器 - Allwinner V3S (Lichee Pi Zero) - Assembly - Timer2


方塊圖


Registers


IRQ Status


Timer2 Ctrl


Timer2 Value


main.s

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    .global _start
       
    .equ GPIO_BASE,  0x01c20800
    .equ TIMER_BASE, 0x01c20c00
   
    .equ PG,                  (0x24 * 6)
    .equ TMR_IRQ_STA_REG,     0x04
    .equ TMR2_CTRL_REG,       0x30
    .equ TMR2_INTV_VALUE_REG, 0x34
    .equ TMR2_CUR_VALUE_REG,  0x38
    .equ CFG0,                0x00
    .equ DATA,                0x10
   
    .arm
    .text
_start:
    .long 0xea000016
    .byte 'e', 'G', 'O', 'N', '.', 'B', 'T', '0'
    .long 0, __spl_size
    .byte 'S', 'P', 'L', 2
    .long 0, 0
    .long 0, 0, 0, 0, 0, 0, 0, 0
    .long 0, 0, 0, 0, 0, 0, 0, 0
             
_vector:
    b reset
    b .
    b .
    b .
    b .
    b .
    b .
    b .
             
reset:
    ldr r0, =GPIO_BASE
    ldr r1, =1
    str r1, [r0, #(PG + CFG0)]
       
    ldr r1, =1
    str r1, [r0, #(PG + DATA)]
   
    ldr r2, =TIMER_BASE
    ldr r3, =187500
    str r3, [r2, #TMR2_INTV_VALUE_REG]
    str r3, [r2, #TMR2_CUR_VALUE_REG]
   
    ldr r3, =(7 << 4) | (1 << 2) | (1 << 1) | (1 << 0)
    str r3, [r2, #TMR2_CTRL_REG]
   
    ldr r4, =(1 << 0)
0:
    ldr r3, [r2, #TMR_IRQ_STA_REG]
    tst r3, #(1 << 2)
    beq 0b
    str r3, [r2, #TMR_IRQ_STA_REG]
       
    eor r1, r4
    str r1, [r0, #(PG + DATA)]
    b 0b
    .end

完成