Assembly Language(1.2.4 c)

Question 1

What is assembly language?

Answer 1

when a program is executing the processor receives instructions from RAM in a sequential order
these instructions are coded in assembly language
decode unit takes assembly language instruction in binary and decodes them into a valid operation

Question 2

What is Little Man Computer(LMC)?

Answer 2

an instruction set designed for educational purposes
contains 11 instructions(mnemonic) to demonstrate important concepts or tracing and writing assembly code

Question 3

ADD

Answer 3

add
0001
1

Question 4

SUB

Answer 4

subtract
0010
2

Question 5

STA

Answer 5

store
0011
3

Question 6

LDA

Answer 6

load
0101
5

Question 7

BRA

Answer 7

branch always
0110
6

Question 8

BRZ

Answer 8

branch if zero
0111
7

Question 9

BRP

Answer 9

branch if positive
1000
8

Question 10

INP

Answer 10

input
1001 1001
9(1)

Question 11

OUT

Answer 11

output
1001 0010
9(2)

Question 12

HLT

Answer 12

end program
0000
0

Question 13

DAT

Answer 13

data location

Question 14

What is tracing?

Answer 14

the process of following the flow of information through each line of program and calculating values or outputs that would occur

Question 15

00 INP
01 STA 05
02 INP
03 ADD 05
04 OUT
05 DAT 00(gets overwritten)

Answer 15

takes input from user
stores inputted data in memory location 05
takes a second input from the user
adds value stored in location 05
outputs result to the console

Question 16

INP(LMC and registers)

Answer 16

loads data inputted by user dirrectyly into the ACC

Question 17

STA(LMC and registers)

Answer 17

sends data from ACC to RAM via MAR and MDR

Question 18

LDA(LMC and registers)

Answer 18

reads data from RAM via MAR and MDR into ACC

Question 19

OUT(LMC and registers)

Answer 19

send value currently in ACC to the console

Question 20

ADD(LMC and registers)

Answer 20

takes data from RAM via MAR and MDR and adds to value currently in ACC

Question 21

SUB(LMC and registers)

Answer 21

takes data from RAM via the MAR and MDR and subtracts it from the value currently in the ACC

Question 22

BRA,BRP,BRZ(LMC and registers)

Answer 22

may instruct the Program Counter (PC) to change the address of the next instruction, which then gets passed to the MAR

Question 23

Branching

Answer 23

there is no multiplication or subtraction so loops of repeated adding and subtracting are needed
there are no while loops so BRA, BRZ and BRP are used

Question 24

Branching BRA

Answer 24

indicates that the memory location in the operand should be the next line executed regardless of the value of the ACC

Question 25

Branching BRZ

Answer 25

indicates that the memory location in the operand should be the next line executed if the ACC is currently 0, otherwise continue executing lines in sequence

Question 26

Branching BRP

Answer 26

indicates that the memory location in the operand should be executed if the ACC is not negative, otherwise continue executing lines in sequence