TRIMUI SMART >> Assembly

PWM0

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參考資訊：
1. pdf

PWM0位於PB4


PWM有兩種運作方式：


PWM位址


CTL


PERIOD


main.s

    .global _start
   
    .equ PWM_BASE,       0x01c21400
    .equ GPIO_BASE,      0x01c20800
    .equ PB_CFG0,        (GPIO_BASE + (0x24 * 1) + 0x00)
    .equ PWM_CH_CTRL,    0x00
    .equ PWM_CH0_PERIOD, 0x04
          
    .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, =PB_CFG0
    ldr r1, =0x20000
    str r1, [r0]

    ldr r0, =PWM_BASE
    ldr r1, =(1 << 4) | (12 << 0)
    str r1, [r0, #PWM_CH_CTRL]

    ldr r1, =(1 << 6) | (1 << 4) | (12 << 0)
    str r1, [r0, #PWM_CH_CTRL]

    ldr r1, =(666 << 16) | (333 << 0)
    str r1, [r0, #PWM_CH0_PERIOD]
0:  
    nop
    b 0b
    .end

完成

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