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35 lines
860 B
35 lines
860 B
9 years ago
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;;;-------------------------------------------------
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;; Configure GPIO
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;;
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Cfg_GPIO PROC
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PUSH {R0, R1, R2, LR}
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; !!! If you don't like the register names,
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; simply change them in the SFR file !!!
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; Enable GPIO clocks
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LDR R2, =RCC_AHBENR ; AHBENR address
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LDR R1, [R2]
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LDR R0, =RCC_AHBENR_GPIOPCEN ; GPIOC enable bit
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ORR R1, R0
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STR R1, [R2]
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; Configure MODER
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LDR R2, =GPIOC_MODER
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LDR R1, [R2]
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LDR R0, =(GPIO_MODER_MODER8 :OR: GPIO_MODER_MODER9); clear bits
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BIC R1, R0
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; Write "OUTPUT" pattern (0x5555...) masked to the two bits
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LDR R0, =(GPIO_MODER_MODER8 :OR: GPIO_MODER_MODER9) & 0x55555555
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ORR R1, R0
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; Store modified value back to MODER
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STR R1, [R2]
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POP {R0, R1, R2, PC}
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ENDP
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;;
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;;;-------------------------------------------------
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END
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