For this LC-3 assembly code .. .ORIG x3000 AND R2,R2,#0 LD R3, FILE COUNT LDR R0

Question

For this LC-3 assembly code ..

.ORIG x3000

AND R2,R2,#0

LD R3, FILE

COUNT LDR R0,R3,#0

BRz END_COUNT

ADD R3,R3,#1

ADD R2,R2,#1

BRnzp COUNT

END_COUNT ADD R4,R2,#0

BRz SORTED

OUTERLOOP ADD R4,R4,#-1

BRnz SORTED

ADD R5,R4,#0

LD R3,FILE

INNERLOOP LDR R0,R3,#0

LDR R1,R3,#1

NOT R2,R1

ADD R2,R2,#1

ADD R2,R0,R2

BRnz SWAPPED

STR R1,R3,#0

STR R0,R3,#1

SWAPPED ADD R3,R3,#1

ADD R5,R5,#-1

BRp INNERLOOP

BRnzp OUTERLOOP

SORTED HALT

FILE .FILL x7000

.END

add the prompts for the user to input a number
add a loop for input to continue until zero is entered
sort the array
print out on the screen “Sorted Array”
print out the sorted array, one number per line. Note this will require conversion of binary integers to ASCII.
You will need to use various IO traps for this assignment.

so an example would look like this

Enter a number <Program output>
3 <User input>
Enter a number <Program output>
2 <User input>
Enter a number <Program output>
5 <User input>
Enter a number <Program output>
0 <User input. Note: this will terminate input>
Sorted Array <Program output>
2
3
5

Explanation / Answer

AND R2, R2, #0 ; Initialize R2 <- 0 (counter)

FILE .FILL x3500 ; File location

; Implementing bubble sort algorithm ; R0 File item ; R1 File item ; R2 Work variable ; R3 File pointer ; R4 Outer loop counter ; R5 Inner loop counter .ORIG x3000 ; Count the number of items to be sorted and store the value in R7

AND R2, R2, #0 ; Initialize R2 <- 0 (counter)

  LEA R0, PROMPT     ;Load address of prompt  TRAP x22           ;Output prompt to display  

LD R3, FILE ; Put file pointer into R3 COUNT LDR R0, R3, #0 ; Put next file item into R0 BRZ END_COUNT ; Loop until file item is 0 ADD R3, R3, #1 ; Increment file pointer ADD R2, R2, #1 ; Increment counter BRNZP COUNT ; Counter loop END_COUNT ADD R4, R2, #0 ; Store total items in R4 (outer loop count) BRZ SORTED ; Empty file ; Do the bubble sort OUTERLOOP ADD R4, R4, #-1 ; loop n - 1 times BRNZ SORTED ; Looping complete, exit ADD R5, R4, #0 ; Initialize inner loop counter to outer LD R3, FILE ; Set file pointer to beginning of file INNERLOOP LDR R0, R3, #0 ; Get item at file pointer LDR R1, R3, #1 ; Get next item NOT R2, R1 ; Negate ... ADD R2, R2, #1 ; ... next item ADD R2, R0, R2 ; swap = item - next item BRNZ SWAPPED ; Don't swap if in order (item <= next item) STR R1, R3, #0 ; Perform ... STR R0, R3, #1 ; ... swap SWAPPED ADD R3, R3, #1 ; Increment file pointer ADD R5, R5, #-1 ; Decrement inner loop counter BRP INNERLOOP ; End of inner loop BRNZP OUTERLOOP ; End of outer loop SORTED HALT

FILE .FILL x3500 ; File location

  PROMPT     .STRINGZ "Enter the Number: "  

.END

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