ONES AND ZEROS COUNT

 ;Program to count the number of ones and zeros in two consecutive memory locations
 AREA dot,data,readonly
 DCB 0x01,0x21
 AREA data1,data
 SPACE 4
 AREA prog,code,readonly
 ENTRY
 mov r2,#2
 ldr r0,=dot
up ldrb r1,[r0],#1
 mov r3,#8
top tst r1,#0x01
 bne addone
 add r7,r7,#1 ;r7 contains the count of number of zeros
 beq skp
addone add r6,r6,#1 ; r6 contains the count of number of ones
skp subs r3,r3,#1
 lsr r1,#1
 bne top
 subs r2,#1
 bne up
 ldr r0,=data1
 str r7,[r0],#4
 str r6,[r0]
s b s

 END