1. Enhancing Data Path M 4-bit Reg X A L U
We can add a memory and a register file to data path as shown
Data from ALU can be written in reg file, memory, and registers
Data from reg file and mem unit can be selected for register input A L U
4-bit
Reg M X
LD1 M2 M1
LD2
OpCode
enable
Keyboard
Mem
Unit
Mem Addr WM EM
File
Reg Addr WR ER

2. Addition for multiply M 4-bit X A L U
For multiplication, we add a shift unit and and M-reg
M-reg can be loaded with output of ALU and copied on bus
Shift unit can shift operand one bit left or right with or without M-register contents
Mem
Unit
Mem Addr WM EM
Reg
File
Reg Addr WR ER A L U
4-bit M X
LD1 M2 M1
LD2
OpCode
Input
enable M-
LDM

3. Complete Block diagram
Mem
Unit
Mem Addr WM EM
Reg
File
Reg Addr WR ER A L U
4-bit M X
LD1 M2 M1
LD2
OpCode
Input
enable M-
LDM