COA-CT2-B1(466-492)

The register that holds the memory address of data is:

• MDR

• PC

• MAR

• IR

The register that holds the instruction currently being executed is:

• MDR

• IR

• MAR

• R1

MAR stands for:

• Memory Address Register

• Main Arithmetic Register

• Machine Address Register

• Memory Access Request

MDR stands for:

• Machine Data Register

• Memory Data Register

• Main Decoder Register

• Memory Device Register

A system bus typically consists of:

• Data, Control, Address lines

• Only Data lines

• Only Control lines

• Only Address lines

Subtraction microoperation is performed using:

• ADD and 2's complement

• SUB directly

• AND gate

• OR gate

The microoperation R1 ← R1 - 1 is:

• DEC

• INC

• CMA

• CLR

Which arithmetic operation produces overflow?

• Logical AND

• Subtraction

• Addition of signed numbers

• XOR

Which logic microoperation clears a register?

• XOR

• AND with 0

• OR

• NOT

The NOT operation is equivalent to:

• Complements all bits

• Sets all bits to 0

• Sets all bits to 1

• Shifts bits left