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WorksheetsA level Computer Science Fetch Decode Execute
Total questions: 11
Worksheet time: 7mins
First Step of the FETCH
The CPU reads the contents of the Program Counter to find the address of the next instruction to be fetched
The address in the MAR is then located in RAM
The contents of the RAM address are moved to the MDR
The instruction in the MDR is copied to the CIR
What happens in FETCH immediately after the CPU reads the contents of the Program Counter to find the address of the next instruction to be fetched
The Program Counter is copied to the CIR
The Program Counter is incremented
The contents of the data bus is read
The contents of the MDR is read
CIR Stands for
Current Instruction RAM
Current Instruction Register
CPU Information Register
Combined Information Register
Combined Instruction Register
The first step in the DECODE step is
The contents of the CIR are divided into instruction and data
The contents of the CIR are copied to the PC.
The contents of the CIR are copied to the RAM.
The contents of the CIR are copied to the ALU.
In the EXECUTE stage the result of a calculation is stored in the ..
ALU
MDR
Control Bus
Accumulator
Operand
The PC contains
Operand
Address
Operator
Data
IN the FETCH step the contents of the address identified by the PC are moved to the
Accumulator
CIR
MAR
PC
Holds the RAM address you want to read to or write from.
MAR
CIR
MDR
Accumulator
What is the YELLOW REGISTER
ACC
MAR
CIR
RAM
In the FETCH step what is copied into the CIR
Contents of Memory
Contents of MBR
Contents of C
Contents of ALU
Direct addressing uses an operand that is
an instruction
data
an address
an op-code
