88 lines
4.3 KiB
NASM
88 lines
4.3 KiB
NASM
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;-------------------------------------------------------------------------------
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; MSP430 Assembler Code Template for use with TI Code Composer Studio
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;
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;
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;-------------------------------------------------------------------------------
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.cdecls C,LIST,"msp430.h" ; Include device header file
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;-------------------------------------------------------------------------------
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.def RESET ; Export program entry-point to
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; make it known to linker.
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.data
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myStr: .cstring "6*8" ; define string
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;-------------------------------------------------------------------------------
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.text ; Assemble into program memory.
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.retain ; Override ELF conditional linking
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; and retain current section.
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.retainrefs ; And retain any sections that have
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; references to current section.
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;-------------------------------------------------------------------------------
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RESET mov.w #__STACK_END,SP ; Initialize stackpointer
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StopWDT mov.w #WDTPW|WDTHOLD,&WDTCTL ; Stop watchdog timer
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;-------------------------------------------------------------------------------
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; Main loop here
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;-------------------------------------------------------------------------------
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main: mov.w #myStr, R4 ; Move the starting address of myStr into register 4
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clr.b R5 ; Use R5 to hold the character
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clr.b R6 ; use r6 for first number
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clr.b R7 ; use R7 for second
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mov.b #0, R3 ; use r3 as counter
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mov.b @R4+, R5 ; get a new character
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cmp.b #58, R5 ; check for ':' character
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jge error ; if equal or greater, jump to error
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cmp.b #48, R5 ; is it a '0'
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jl error ; if less, jump to error
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mov.b R4, R6 ; move first number into Register 6
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mov.b @R4+, R5 ; get a new character
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cmp #'*', R5 ; is it '*'
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jne error ; if not equal, jump to error
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mov.b @R4+, R5 ; get next character
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cmp.b #58, R5 ; check for ':' character
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jge error ; if equal or greater, jump to error
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cmp.b #48, R5 ; is it a '0'
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jl error ; if less, jump to error
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mov.b @R4+, R5 ; get next char
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cmp.b #0, R5 ; is it NULL
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jne error ; error if not
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mov.b R4, R7 ; move next number to register 7
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cmp.b R7, R5 ; which is less
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jge firstNum ; if first is greater jump to firstNum
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jl secondNum ; less than, jump to secondNum
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firstNum: cmp R3, R5 ; comparing r3 to loop top
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jz endOne ; when 0 end loop
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dadd.b R7, R7 ; add bigger number to itself
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dadd.b r3,r3 ; increment counter
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jmp firstNum ; jump to firstNum
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secondNum: cmp R3, R7 ; comparing r3 to loop top
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jz endTwo ; when 0 end loop
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dadd.b R5, R5 ; add bigger number to itself
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dadd.b r3,r3 ; increment counter
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jmp secondNum ; jump to secondNum
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error: mov #0xFF, &P2OUT ; move FF to P2OUT
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jmp errorEnd
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endOne: mov.w R7,&P2OUT ; Write result in P1OUT (not visible on port pins)
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endTwo: mov.w R5,&P2OUT ; Write result in P1OUT (not visible on port pins)
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errorEnd:
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bis.w #LPM4, SR ; LPM4
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nop ; Required only for debugger
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;-------------------------------------------------------------------------------
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; Stack Pointer definition
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;-------------------------------------------------------------------------------
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.global __STACK_END
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.sect .stack
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;-------------------------------------------------------------------------------
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; Interrupt Vectors
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;-------------------------------------------------------------------------------
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.sect ".reset" ; MSP430 RESET Vector
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.short RESET
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