Question

Consider the following LC-3 assembly program. Assume the role of the assembler:

.ORIG x3000
LEA R1, DATA
LD R2, NUM
LOOP
BRz DONE
STR R2, R1, #0
ADD R1, R1, #1
ADD R2, R2, #-1
BR LOOP
DONE
NUM .FILL x0004
DATA BLKW 8
.END

Show the contents of memory as defined by the assembly (eg. binary encoding of the program) and the symbol table.

Answer 1

The LC-3 assembly program provided gives the contents of memory and the symbol table.

Step-by-step explanation:

The LC-3 assembly program given is:

.ORIG x3000
LEA R1, DATA
LD R2, NUM
LOOP BRz DONE
STR R2, R1, #0
ADD R1, R1, #1
ADD R2, R2, #-1
BR LOOP
DONE
NUM .FILL x0004
DATA BLKW 8
.END

The contents of memory as defined by the assembly are:

x3000: 1110 0001 0000 0010
x3001: 0010 0010 1000 0001
x3002: 0101 1001 1111 1111
x3003: 0000 1010 0000 0001
x3004: 0000 1000 0001 1111
x3005: 0000 0010 1111 1111
x3006: 0000 0000 0000 0000
x3007: 0000 0000 0000 0000
x3008: 0000 0000 0000 0000
x3009: 0000 0000 0000 0000
x300A: 0000 0000 0000 0000
x300B: 0000 0000 0000 0000
x300C: 0000 0000 0000 0000
x300D: 0000 0000 0000 0000
x300E: 0000 0000 0000 0000
x300F: 0000 0000 0000 0000

The symbol table is as follows:

DATA: x300B
NUM: x3004
LOOP: x3003
DONE: x3008