Instruction Queuing Unit

Instruction Queuing Unit
A unit to hold a queue of instructions and place these into the cache.

Prefetch Control Unit

Prefetch Control Unit 
A unit to fetch instructions in advance and data in advance from the memory units. 

Instruction Decoder

Instruction Decoder
The circuit to decode the opcode of the instruction and direct he control accordingly.

Instruction Register

Instruction Register
A Register to hold the current instruction for execution. 

Control Unit

Control Unit
To control and sequence all the processing actions during an instruction execution. 

ALU (Arithmetic and Logic Unit)

ALU (Arithmetic and Logic Unit)
A unit to perform arithmetic and logic operations as per the instructions.

Arithmetic Unit Registers

Arithmetic Unit Registers
Registers hold the input and output operands and flags with ALU.