Question

A block of data is stored from memory location 4501H and onwards. The length of the block is stored at memory location 4500H. Write an  Assembly Language Program to fmd the sum of block of data. Store the two byte result from memory location 4600 H.

Answer 1

Label	Mnemonics	Comments
	LXI H, 4500 H	; Set HL pointer to 4500 H
	MOV C, M	; Get count in register C
	MVI A, 00H	; Make LSB’s of sum = 00
	MOV B, A	; Make MSB’s of sum = 00
LOOP :	INX H	; Set HL to point num in series
	ADD M	; Previous No. + Next No
	JNC AHEAD	; Is carry ? No, goto AHEAD
	INR B	; Yes, add carry to MSB’s of sum
AHEAD :	DCR C	; Decrement count
	JNZ LOOP	; Is count = 0 ? No, jump to LOOP
	STA 4600 H	; Store LSB’s of the sum to 4600 H
	MOV A, B	; Get MSB’s of sum in accumulator
	STA 4601 H	; Store MSBs
	RST 1.0	; Restart