ARM code: Assembly code to add numbers from array

    ARM processor is used in all the Embedded systems that are being built now. Here I explain ARM assembly program to add numbers declared in an array.

ALGORITHM

Start
Create a array of numbers
Initialize a counter register to number of elements in array
Load base address of array to a register
Load value to a temporary register
Add and store number in destination register
Decrement counter value
Repeat steps 5-7 till counter value becomes zero
Stop

Here is a example code to add numbers in array with 5 elements.

CODE

      AREA program,CODE,READONLY
      ENTRY
      MOV R0,#5              ; Initializing counter register
      LDR R1,=array          ; Loading base address to a register
loop  LDR R2,[R1],#4         ; Loading value from array and updating(increment) the address
      ADD R3,R3,R2           ; Sum is stored in R3 register
      SUB R0,R0,#1           ; Decrementing counter value
      CMP R0,#00             ; Checking counter value
      BNE loop
array DCD 0x00000001,0x000000AF,0x00000002,0x00000DC,0x000001FB
      END