8085 Micro-Processor Programs

Transfer a data block using 8085

Ø   An Assembly Language Program to transfer a data block without overlap using 8085?

Algorithm

1)      Load the DE pair with the destination address.

2)      Load the HL pair with the count of elements in the data block.

3)      Load element in the data block.

4)      Increment the source address.

5)      Copy the element to the accumulator and then transfer it to the destination address.

6)      Increment destination address.

7)      Decrement the count.

8)      If Count = 0 then go to the next step else go to step 3.

9)      Terminate the program.

Program

MEMORY	LABEL	MNEMONIC	HEX CODE	COMMENT
4200		LXI D,4500	11	Load destination address in DE pair
4201			00
4202			45
4203		LXI H,4100	21	Load the count in HL pair
4204			00
4205			41
4206		MOV C,M	4E	Copy the count to register C
4207	LOOP	INX H	23	Increment memory
4208		MOV A,M	7E	Copy element to Accumulator
4209		STAX D	12	Store the element to the address in the DE pair
420A		INX D	13	Increment destination address
420B		DCR C	OD	Decrement count
420C		JNZ LOOP	C2	Jump on non-zero to the label LOOP
420D			07
420E			42
420F		HLT	76	Program ends

Observation

Input at           4100    :           04_H

                        4101    :           06_H

                        4102    :           07_H

                        4103    :           12_H

                        4104    :           03_H

Output at         4500    :           06_H

                        4501    :           07_H

                        4502    :           12_H

                        4503    :           03_H

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Occurrence of an 8-bit number using 8085

Ø   An Assembly Language Program to find the occurrence of an 8-bit number in a given array of elements using 8085?

Algorithm

1)      Load the HL pair with the address of the element to be found.

2)      Copy the element to accumulator.

3)      Load the count to the C register.

4)      Increment the memory.

5)      Compare accumulator and memory.

6)      If ZF = 0 go to next step else go to step 8.

7)      Increment the occurrence by 1.

8)      Decrement count by 1.

9)      If count = 0 go to next step else go to step 4.

10)  Copy the number of occurrence to accumulator and then to memory.

11)  Terminate the program.

Program

MEMORY	LABEL	MNEMONIC	HEX CODE	COMMENT
4300		MVI B,00	06	Initialize B as 0
4301			00
4302		LXI H,4400	21	Load HL pair with the address of the data whose occurrence is to be found
4303			00
4304			44
4305		MOV A,M	7E	Copy the data to the Accumulator
4306		INX H	23	Increment memory
4307		MOV C,M	4E	Copy the count to the C register
4308	LOOP	INX H	23	Increment memory
4309		CMP M	BE	Compare memory and accumulator
430A		JNZ GOTO	C2	Jump on non-zero to the label GOTO
430B			0E
430C			43
430D		INR B	04	Increment occurrence
430E	GOTO	DCR C	0D	Decrement count
430F		JNZ LOOP	C2	Jump on non-zero to the label LOOP
4310			08
4311			43
4312		MOV A,B	78	Copy the number of the occurrence to the Accumulator
4313		STA 4415	32	Store the accumulator content to 4415
4314			15
4315			44
4316		HLT	76	Program ends

Observation

Input at             4400    :           06_H        ------------         Number to be checked

                        4401    :           04_H        ------------         Count

                        4402    :           03_H

                        4403    :           06_H

                        4404    :           06_H

                        4405    :           06_H

Output at         4415    :           03_H        ------------         Number of occurrence

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