Question

on pour assium prtion Attempt each question onty oce Question 1: 120 Marks] CLO-02 Write an assembly language program to count all non-zcro bytes in the entire scratch pad of general -7FH) of 80S1 microcontroller. The counting value is stored in accumulator A, and each non-zero bvte is cleared (set to value zero). 9s Question#2 120 Marksj CLO-03 ?3 onsider a disk mounted on a DC motor that has a variable speed. There are 4 small holes (hl, h2, h3 and h4) on the disk (90 degrees apart). In each revolution, the system generates four pulses (one pulse against each hole). The disk of motor is connected with 8051 such that pulse of each hole is sensed at oin P3.dw while revolving. Spged of the motor is reasonably large such that the pulses are of very short duration rite an assembly language program to calculate speed of motor in RPM (revolutions per minute) Maximum value of speed.can be 2400RPM Store the lower byte of answer in RO and higher in R1 of bank0. (Hin First calcutate number of reyolutions per second and then find speed)

Answer 1

Answer :- 1) The 8051 assembly code has been written below-

MOV R1, #40H ; register R1 = 0x40
MOV R2, #00H ; clear R2 register
MOV R3, #7FH ; R3 = 0x7F i.e. end address
Loop1 : ; label named as Loop1
MOV A, @R1 ; A = read memory address in R1
CJNE MakeZero ; if A is not zero, go to label named as MakeZero
INC R2 ; if A = 0 then increment the value in R2
INC R1 ; R1 = next memory address
CJNE R1, #7FH, Loop1 ; if R1 is not equal to 7FH then goto Loop1
JMP EndProg ; jump to label EndProg

MakeZero : ; label named as MakeZero
MOV A, #00H ; A = 0
MOV @R1, A ; make value as zero at address in R1
INC R1 ; R1 = next memory address
CJNE R1, #7FH, Loop1 ; if R1 is not equal to 7FH then goto Loop1

EndProg : ;label named as EndProg
MOV A, R2 ; copy the count value to the Accumulator
Here : JMP Here ; infiite loop, end of program