8-bit HEX to BCD convertor

17 July 2011

1 min read

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This subroutine converts 8 bit Hexadecimal number into its equivalent BCD value. The number to be converted should be in the Accumulator. The output BCD number is stored in R0 & R1. R0 is used to save the MSB i.e. the hundreds place & R1 stores the LSB i.e. the Tens & Units place.

hextobcd:
mov r0,#00h
mov r1,#00h
cjne a,#00h,c1_hextobcd	//If number is not 0 then continue
ret

c1_hextobcd:
*clr c*
mov b,#100	*//First divide by 100*
div ab
mov r0,a	*//save MSB in R0*
clr c
mov a,b
mov b,#10	*//Divide by 10*
div ab
swap a
mov r1,a	*//save the tens place in the Higher nibble of R1*
mov a,b
orl a,r1
mov r1,a	*// save the tens place in the Lower nibble of R1*
ret