8086 program to find the min value in a given array

Problem – Write a program to find the min value in a given array in assembly 8086 microprocessor 

Example – Assumptions – Starting address of input array is 0500 and store the result at address 0600 

Algorithm –

1. Assign value 500 in SI and 600 in DI
2. Move the contents of [SI] in CL and increment SI by 1
3. Assign the value 00 H to CH
4. Move the content of [SI] in AL
5. Decrease the value of CX by 1
6. Increase the value of SI by 1
7. Move the contents of [SI] in BL
8. Compare the value of BL with AL
9. Jump to step 11 if carry flag is set
10. Move the contents of BL in AL
11. Jump to step 6 until the value of CX becomes 0, and decrease CX by 1
12. Move the contents of AL in [DI]
13. Halt the program

Program –

MEMORY ADDRESS	MNEMONICS	COMMENTS
0400	MOV SI, 500	SI <- 500
0403	MOV DI, 600	DI <- 600
0406	MOV CL, [SI]	CL <- [SI]
0408	MOV CH, 00	CH <- 00
040A	INC SI	SI <- SI+1
040B	MOV AL, [SI]	AL <- [SI]
040D	DEC CX	CX <- CX-1
040E	INC SI	SI <- SI+1
040F	MOV BL, [SI]	BL <- [SI]
0411	CMP AL, BL	AL-BL
0413	JC 0417	Jump if carry is 1
0415	MOV AL, BL	AL <- BL
0417	LOOP 040E	Jump if CX not equal to 0
0419	MOV [DI], AL	[DI] <- AL
041B	HLT	End of the program

Explanation –

1. MOV SI, 500 assigns 500 to SI
2. MOV DI, 600 assigns 600 to DI
3. MOV CL, [SI] moves the content of [SI] to CL register
4. MOV CH, 00 assign 00 to CH register
5. INC SI increase the value SI by 1
6. MOV AL, [SI] moves the content of [SI] to AL register
7. DEC CX decrease the content of CX register by 1
8. INC SI increase the value SI by 1
9. MOV BL, [SI] moves the content of [SI] to BL register
10. CMP AL, BL subtract the value of BL register from AL and it modify flag registers
11. JC 0417 jump to 0417 address if carry flag is set
12. MOV AL, BL moves the content of BL register to AL register
13. LOOP 040E runs loop till CX not equal to Zero and decrease the value of CX by 1
14. MOV [DI], AL moves the content of AL to [DI]
15. HLT stops the execution of program