Average and Square Root Using 8085

AVERAGE OF N NUMBERS

AIM:

      To write an assembly language program that finds the average of N numbers and executes the program using 8085 microprocessor kit.

APPARATUS REQUIRED:

8085 microprocessor kit, power supply.

ALGORITHM:

STEP 1: Load HL register pair with a memory pointer.

STEP 2: Get the count to B register and clear accumulator.

STEP 3: Push the count to stack pointer.

STEP 4: Increment memory pointer.

STEP 5: Add the content of memory location to accumulator.

STEP 6: If carry results increment D register.

STEP 7: Decrement count. If it is not zero go to STEP 4.

STEP 8: Else move the sum to E register.

STEP 9: Get the count from stack pointer.

STEP10: Subtract the count from sum(content of DE pair).

STEP11:If the subtraction results a carry add the count to the result and get the remainder

STEP12: Otherwise increment B register content and go to STEP10.

STEP 13: Store the quotient and remainder in successive memory location.

PROGRAM:

MEMORY LOATION	MAHINE CODE	LABEL	MNEMONICS	COMMENTS
4100	21,00,42		LXI H, 4200	Initialize HL register pair with memory pointer
4103	46		MOV B,M	Transfer the memory content to B register
4104	C5		PUSH B	Push the content of B register to stack pointer
4105	AF		XRA A	Clear accumulator
4106	57		MOV D,A	Clear D register
4107	5F		MOV E,A	Clear E register
4108	23	LOOP1	INX H	Increment memory pointer
4109	86		ADD M	Add the content of memory location to accumulator
410A	D2,0E,41		JNC LOOP2	Jump on no carry to LOOP2
410D	14		INR D	Increment D register content
410E	05	LOOP2	DCR B	Decrement B register content
410F	C2,08,41		JNZ LOOP1	Jump on zero to LOOP1
4112	5F		MOV E,A	Move the content of accumulator to E register
4113	C1		POP B	Retrieve the content of B register from stack
4114	26,00		MVI H,00	Clear H register
4116	68		MOV L,B	Move the [B] to L register
4118	7B	LOOP4	MOV A, E	Mover the[E] content to accumulator
4119	95		SUB L	Subtract [L] content from accumulator
411A	5F		MOV E,A	Move the accumulator content to E register
411B	7A		MOV A, D	Move the[D] to accumulator
411C	9C		SBB H	Subtract [H] from accumulator through borrow
411D	DA,25,41		JC LOOP3	Jump on carry to LOOP3
4120	57		MOV D,A	Move accumulator content to D register
4121	04		INR B	Increment B register
4122	C3,18,41		JMP LOOP 4	Jump to LOOP4
4125	7B	LOOP3	MOV A,E	Move[E] to accumulator
4126	85		ADD L	Add [L] with accumulator content
4217	5F		MOV E,A	Move accumulator content to E register
4128	78		MOV A,B	Move [B] register to accumulator
4129	32,00,43		STA 4300	Store the accumulator content in 4300
412C	EB		XCHG	Exchange [DE] With [HL]
412D	22,01,43		SHLD 4301	Store the remainder in 4301 and 4302
4130	76		HLT	Ends execution

SAMPLE INPUT AND OUTPUT:

MEMORY LOCARION	INPUT	MEMORY LOCATION	OUTPUT

RESULT:

Thus an 8085 assembly language program that finds average of N numbers was written and executed using microprocessor kit.

Questions and Answers

1. What is meant by looping and indexing? explain

2. Explain about following instructions.

i) LHLD ii) RAR iii) SPHL

3. What are the different addressing modes in 8085? explain in detail.

4. Differentiate between memory mapped I/O and peripheral I/O?

EXERCISE

1. Write an 8085 assembly language program to compute the HCF of two 16-bit numbers stored in word locations X and X+2. Store the result in word location X+4.

2. Write an 8085 assembly language program to compute the LCM of two 16-bit numbers stored in word locations X and X+2. Store the result in word location X+4 and X+6.

3. Write an 8085 assembly language program to compute the HCF of two 4-digit BCD numbers stored in word locations X and X+2. Store the result in word location X+4.

4. Write an 8085 assembly language program to compute the LCM of two 4-digit BCD numbers stored in word locations X and X+2. Store the result in word location X+4.

SQUARE ROOT OF A NUMBER

AIM:

To write an assembly language program to find the square root of a number and execute the program using 8085 microprocessor kit.

APPARATUS REQUIRED:

8085 microprocessor kit, power supply.

METHOD TO FIND SQUARE ROOT OF A NUMBER:

Suppose that X is the square root of number N. To find the square root, we derive the following equation

Let X²=N

Add X² on both sides. Then

2 X²=N+ X²

X²=(N+ X²)/2

X=(N+ X²)/(2*X)

X=((N/X)+X)/2

Xnew= ((N/X)+X)/2

To find the square root of a given number we provide an initial guess X. With this value we calculate Xnew and compare it with X. If Xnew=X, it gives the result .If Xnew ≠ X then we take the Xnew as X and using the equation we find Xnew. This process is repeated until Xnew=X.

ALGORITHM:

Step1: load HL register pair with a memory pointer.

Step2: get the number into accumulator and E register.

Step3: increment memory pointer.

Step4: get the initial guess to D and B registers.

Step5: call the division program.

Step6: add the initial guess with the accumulator.

Step7: divide the content of accumulator by 2 using division program.

Step8: if the calculated value is equal to guess, store the result in the memory location.

Step9: else take calculated value as guess and go to step5.

PROGRAM:

MEMORY LOCATION	MACHINE CODE	LABEL	MNIMONICS	COMMENTS
4100	21,00,42		LXIH, 4200	Initialize HL register pair with memory pointer
4103	7E		MOV A, M	Transfer the content of memory location to accumulator
4104	5E		MOV E, M	Transfer the content of memory location to E register
4105	23		INX H	Increment memory pointer
4106	56		MOV D, M	Move the initial guess to D register
4107	46		MOV B,M	Move the initial guess to to B register
4108	0E,00	LOOP3	MVI C,00	Clear C register
410A	CD,1E,41		CALL DIV	Call division program
410D	80		ADDB	Add guess with accumulator
410E	06,02		MVI B,02	Move 02 to B register
4110	0E,00		MVI C,00	Clear C register
4112	CD,1E,41		CALL DIV	Call division program
4115	7A		MOV A,D	Move [D] to accumulator
4116	51		MOV D,C	Move [C] to D register
4117	B9		CMP C	Compare the guess with calculated value
4118	C2,28,41		JNZ LOOP1	Jump on no zero to loop1
411B	23		INX H	Increment memory pointer
411C	71		MOV M,C	Move [C] to memory location
411D	76		HLT	Ends execution
411E	90	DIV	SUB B	Subtract [B] from accumulator
411F	DA,26,41		JC LOOP2	Jump on carry to loop2
4122	0C		INR C	Increment C register content
4123	C3,1E,41		JMP DIV	Jump to division program
4126	79	LOOP2	MOV A,C	Move [C] to accumulator
4127	C9		RET	Return to main program
4128	7B	LOOP1	MOV A,E	Move[E] to accumulator
4129	41		MOV B,C	Move [B] to C register
412A	C3,08,41		JMP LOOP3	Jump to loop3

SAMPLE INPUT AND OUTPUT:

INPUT DATA [4200]	OUTPUT DATA [4202]

RESULT:

Thus an 8085 assembly language program that finds the square root of a given number was written and executed using microprocessor kit.

Questions and answers:

1. Explain in detail about interrupt structure of 8085?

2. Write about the following instructions.

i) PUSH

ii) XTHL

iii) PCHL

3 What is the function of HOLD pin in 8085?

4. Differentiate between 8088 and 8086?

EXERCISES:

1. Write an 8085 assembly language program to convert a 32 bit binary number stored in locations X to X+3 to equivalent BCD number. Store the result in locations X+4 and X+7.

2. Write an 8085 assembly language program to convert a 8-digit BCD number stored in locations X to X+3 to equivalent binary number. Store the result in locations X+4 to X+7.

3. Write an 8085 assembly language program to sort a given set of 16-bit numbers in ascending order using Bubble sort algorithm. The number of elements to be sorted is provided in location X. The elements are in word locations starting from X+1.

4. Write an 8085 assembly language program to sort a given set of 16-bit numbers in descending order using Selection sort algorithm. The number of elements to be sorted is provided in location X. The elements are in word locations starting from X+1.