8085 program to find minimum value of digit in the 8 bit number

In this program we will see how to find the minimum digit from a two-digit number.

Problem Statement

Write 8085 Assembly language program to find the minimum digit from a two-digit number. The number is stored at location 8000H, store the result at 8050H.

Discussion

Here we are performing this task by using masking operation. Each digit takes one nibbles. We are masking the upper nibble by ANDing with 0FH (0000 1111). Store the lower nibble into another register. After that, we are taking the upper nibble. To get it, we are shifting the number to the right four times to convert lower nibble to upper nibble. Now again performing the masking operation the upper nibble is taken. By comparing them we can find the minimum one.

Input

Address	Data
…	…
8000	78
…	…

Flow Diagram

 

Program

Address	HEX Codes	Labels	Mnemonics	Comments
F000	3A, 00, 80		LDA 8000H	Take the number from memory
F003	47		MOV B,A	Copy the content of A to B
F004	E6, 0F		ANI 0FH	Mask the upper nibble
F006	4F		MOV C,A	Store the lower nibble into C
F007	78		MOV A,B	Take number from B to A
F008	07		RLC	Rotate A content to the left four times
F009	07		RLC
F00A	07		RLC
F00B	07		RLC
F00C	E6, 0F		ANI 0FH	Take the lower nibble
F00E	B9		CMP C	Compare C with A
F00F	DA, 13, F0		JC STORE	If CY = 1, store A to memory
F012	79		MOV A,C	Otherwise take C into A
F013	32, 50, 80	STORE	STA 8050H	Store result into memory
F016	76		HLT	Terminate the program

Output

Address	Data
…	…
8050	07
…	…