Hi asghar,

following an example of the subtraction method for 16 bit.
It is faster than the division method, since the 8051 have no 16 bit or 32 bit division instruction.


;input: R7, R6 = 16 bit value 0 ... 65535
;output: R7, R6, R5, R4, R3 = digits
;cycle: 37 .. 220
;bytes: 44
;
hex2bcd:
mov a, r7
mov r3, a
mov a, r6
mov r7, #-1
?bcd1: inc r7
add a, #low(-10000)
xch a, r3
addc a, #high(-10000)
xch a, r3
jc ?bcd1
mov r6, #10
?bcd2: dec r6
add a, #low(1000)
xch a, r3
addc a, #high(1000)
xch a, r3
jnc ?bcd2
mov r5, #-1
inc r3
?bcd3: inc r5
add a, #low(-100)
jc ?bcd3
djnz r3, ?bcd3
mov r4, #10
?bcd4: dec r4
add a, #10
jnc ?bcd4
mov r3, a
ret


Peter