Lukas Bielesch / DEBUG_F042F6P6

debug tool for STM32F042F6P6

check_1_bit.s

Committer:
bieleluk
Date:
2019-04-15
Revision:
0:98789a3f7363
Child:
24:bc7c4e8f3fe0

File content as of revision 0:98789a3f7363:

    AREA asm_func, CODE, READONLY
; Export my_asm function location so that C compiler can find it and link
    EXPORT check_1_bit
check_1_bit

    PUSH {LR}


    ;R0 = GPIOx
    ;R1 = offset
    ;r2 = pin_number
    

    LDR R3, [R0, R1]
    
    LDR R0, =31
    SUBS R0,R2
        
    LSLS R3,R3,R0
    LSRS R3,#31
    
    MOVS R0,R3
    
    POP {PC}

    ALIGN
    END