Lecture 4

Question 1

use What gate to set bits

Answer 1

Or gate and use 1

Question 2

use What gate to clears bits

Answer 2

And gate and use 0

Question 3

use What gate to toggle bits

Answer 3

Use xor gate and use 1

Question 4

Write a program to compute 1 + 2 + 3 + … + n and save the sum at 0x11 and 0x10.

Answer 4

DCOUNT EQU 10
ACOUNT EQU 0C
MOVLW DCOUNT
MOVWF ACOUNT, f
CLRW
LOOP ADDWF ACOUNT, w
           DECFSZ ACOUNT, f
           GOTO LOOP
MOVWF 11
MOVWF 10

Question 5

Write a program to do the NOP instruction 50000 times.

Answer 5

DCOUNT1 EQU 100
DCOUNT2 EQU 500
ACOUNT1 EQU 0C
ACOUNT2 EQU 0D
MOVLW DCOUNT1
MOVWF ACOUNT1
LOOP1 MOVLW DCOUNT2
            MOVWF ACOUNT2
LOOP2 NOP
             DECFSZ ACOUNT2,1
             GOTO LOOP2
             DECFSZ ACOUNT1,1
             GOTO LOOP1