Part III Machine Code and Memory Usage Three (3) points for each instruction Ple
ID: 2291391 • Letter: P
Question
Part III Machine Code and Memory Usage
Three (3) points for each instruction
Please study the following assembly program, then, fill out the table on the next page.
ORG $4000
LDAA #$45
LDAB #$2A
ABA
STAA $1000
LDAA $1050
SUBA $1051
STAA $1001
SWI
Note: When downloading the machine executable code to a microcontroller’s memory, the assembler directive ORG tells a microcontroller where the executable code will be stored in the memory.
For this assembly program, “ORG $4000” tells a microcontroller that the executable program will be stored in the microcontroller’s memory starting at memory location $4000. The entire executable code will be stored in memory in the order of opcode, then, operand, instruction after instruction, consecutively. Please provide memory address for each opcode, and each operand. Please also note that the memory address is provided for each byte.
Assembly Code
Machine Code
Memory Address for
Instruction
Opcode
Operand
Opcode
Operand
LDAA #$45
$86
$45
LDAB #$2A
$C6
$2A
ABA
$18 $06
STAA $1000
$7A
$10 $00
LDAA $1050
$B6
$10 $50
SUBA $1051
$B0
$10 $51
STAA $1001
$7A
$10 $01
SWI
$3F
Assembly Code
Machine Code
Memory Address for
Instruction
Opcode
Operand
Opcode
Operand
LDAA #$45
$86
$45
LDAB #$2A
$C6
$2A
ABA
$18 $06
STAA $1000
$7A
$10 $00
LDAA $1050
$B6
$10 $50
SUBA $1051
$B0
$10 $51
STAA $1001
$7A
$10 $01
SWI
$3F
Explanation / Answer
Assembly Code
Machine Code
Memory Address for
Instruction
Opcode
Operand
Opcode
Operand
LDAA #$45
$86
$45
$4000
$4001
LDAB #$2A
$C6
$2A
$4002
$4003
ABA
$18 $06
$4004 $4005
STAA $1000
$7A
$10 $00
$4006
$4007 $4008
LDAA $1050
$B6
$10 $50
$4009
$400A $400B
SUBA $1051
$B0
$10 $51
$400C
$400D $400E
STAA $1001
$7A
$10 $01
$400F
$4010 $4011
SWI
$3F
$4012
Assembly Code
Machine Code
Memory Address for
Instruction
Opcode
Operand
Opcode
Operand
LDAA #$45
$86
$45
$4000
$4001
LDAB #$2A
$C6
$2A
$4002
$4003
ABA
$18 $06
$4004 $4005
STAA $1000
$7A
$10 $00
$4006
$4007 $4008
LDAA $1050
$B6
$10 $50
$4009
$400A $400B
SUBA $1051
$B0
$10 $51
$400C
$400D $400E
STAA $1001
$7A
$10 $01
$400F
$4010 $4011
SWI
$3F
$4012