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bitbang.S
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bitbang.S
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#include <bitbang.h>
.include "m0delay.S"
.cpu cortex-m0
.fpu softvfp
.section .bss
.thumb
.section .text.bitbang,"ax",%progbits
.align 2
.global bitbang
.code 16
.thumb_func
.type bitbang, %function
bitbang:
.syntax unified
.thumb
push {r4-r7}
movs rCLK, #(MASK_CLK)
movs rMASK, #(MASK_DATA)
bitbang_loop:
/* 0 + 2 */ ldrb rBYTE, [rBUF]
/* 2 + 1 */ lsrs rOUT, rBYTE, #7
/* 3 + 1 */ ands rOUT, rMASK
/* 4 + 2 */ strb rOUT, [rGPIO, #GPIO_ODR_OFFSET]
/* 6 + 22 */ delay rTMP, 22
/* 28 + 2 */ str rCLK, [rGPIO, #GPIO_BSRR_OFFSET]
/* 30 + 18+2 */ delay rTMP, 20
/* 2 + 1 */ lsrs rOUT, rBYTE, #6
/* 3 + 1 */ ands rOUT, rMASK
/* 4 + 2 */ strb rOUT, [rGPIO, #GPIO_ODR_OFFSET]
/* 6 + 22 */ delay rTMP, 22
/* 28 + 2 */ str rCLK, [rGPIO, #GPIO_BSRR_OFFSET]
/* 30 + 18+2 */ delay rTMP, 20
/* 2 + 1 */ lsrs rOUT, rBYTE, #5
/* 3 + 1 */ ands rOUT, rMASK
/* 4 + 2 */ strb rOUT, [rGPIO, #GPIO_ODR_OFFSET]
/* 6 + 22 */ delay rTMP, 22
/* 28 + 2 */ str rCLK, [rGPIO, #GPIO_BSRR_OFFSET]
/* 30 + 18+2 */ delay rTMP, 20
/* 2 + 1 */ lsrs rOUT, rBYTE, #4
/* 3 + 1 */ ands rOUT, rMASK
/* 4 + 2 */ strb rOUT, [rGPIO, #GPIO_ODR_OFFSET]
/* 6 + 22 */ delay rTMP, 22
/* 28 + 2 */ str rCLK, [rGPIO, #GPIO_BSRR_OFFSET]
/* 30 + 18+2 */ delay rTMP, 20
/* 2 + 1 */ lsrs rOUT, rBYTE, #3
/* 3 + 1 */ ands rOUT, rMASK
/* 4 + 2 */ strb rOUT, [rGPIO, #GPIO_ODR_OFFSET]
/* 6 + 22 */ delay rTMP, 22
/* 28 + 2 */ str rCLK, [rGPIO, #GPIO_BSRR_OFFSET]
/* 30 + 18+2 */ delay rTMP, 20
/* 2 + 1 */ lsrs rOUT, rBYTE, #2
/* 3 + 1 */ ands rOUT, rMASK
/* 4 + 2 */ strb rOUT, [rGPIO, #GPIO_ODR_OFFSET]
/* 6 + 22 */ delay rTMP, 22
/* 28 + 2 */ str rCLK, [rGPIO, #GPIO_BSRR_OFFSET]
/* 30 + 18+2 */ delay rTMP, 20
/* 2 + 1 */ lsrs rOUT, rBYTE, #1
/* 3 + 1 */ ands rOUT, rMASK
/* 4 + 2 */ strb rOUT, [rGPIO, #GPIO_ODR_OFFSET]
/* 6 + 22 */ delay rTMP, 22
/* 28 + 2 */ str rCLK, [rGPIO, #GPIO_BSRR_OFFSET]
/* 30 + 18+2 */ delay rTMP, 20
/* 2 + 1 */ lsrs rOUT, rBYTE, #0
/* 3 + 1 */ ands rOUT, rMASK
/* 4 + 2 */ strb rOUT, [rGPIO, #GPIO_ODR_OFFSET]
/* 6 + 22 */ delay rTMP, 22
/* 28 + 2 */ str rCLK, [rGPIO, #GPIO_BSRR_OFFSET]
/* 30 + 9 */ delay rTMP, 20
/* 39 + 1 */ adds rBUF, rBUF, #1
/* 40 + 1 */ subs rSIZE, rSIZE, #1
/* 41 + 1|3 */ beq 0f
/* 42 + 3 + 3 */ b bitbang_loop
0:
/* 44 + 1 */ movs rOUT, #0
/* 45 + 3 + 4 */ delay rTMP, 7
/* 4 + 2 */ strb rOUT, [rGPIO, #GPIO_ODR_OFFSET]
pop {r4-r7}
bx lr
.size bitbang, .-bitbang