4-2/4-3 MARIE Flashcards
Which of the following is an example of unconditional branching in MARIE’s architecture?
JUMP
Which of the following CPU components is responsible for fetching and decoding instructions?
The Control Unit
Decoding the instruction must always take place before an instruction is executed.
True
The JUMP instruction will change the value stored in which location?
Program Counter
Which of the following are the components of an instruction in MARIE’s architecture?
Address, Opcode
In MARIE’s architecture, explain what action is taken by the following RTN statement.
IR <– M[MAR]
Would the statement be categorized as a step in fetch, decode, or execute?
It is moving an instruction from MM into the IR. It is part of fetch.
What data would the memory address register (MAR) hold in MARIE? Where would data placed in the MAR be sent after being written into the register?
The MAR holds a memory address. The address is always sent via a direct connection to main memory when reading or writing main memory.
Evaluate the following instruction (MARIE architecture) to determine its human-readable opcode (example: LOAD) and the hexadecimal number of the specified memory address. An example answer format is “JUMP 123”.
0011001000011110
0011 0010 0001 1110
0011 = add x
0010 = 2
0001 = 1
1110 = E
ADD 21E
In one or two sentences, what does following simple program do (MARIE architecture)?
LOAD 100
STORE 200
LOAD 300
STORE 400
ADD 200
HALT
The program moved a stored value from 100 to 200, then moves a stored value from 300 to 400. Afterward, it adds the stored value at 200 to the AC value (300/400) and halts.