Very Large Integrated Circuit (VLSI) is a domain where the nano work has been done over millions of transistors and diode and even on other electronics components. Every electronics devices available in market definitely consist of tiny electronics component. Funnel shifter is one of the most important element in any macro electronics devices which is responsible to do logical shifting of binary bits. So, how to make it using electric software and do testing whether the function which has been applied to make this element is right or not that is described here. For more details : https://github.com/shahsamkit73/funnel-shifter

1. What Is Funnel Shifter ?
• Shifters are very important element which is generally used in
microcontroller and microprocessor design for arithmetic shifting,
logical shifting and rotation function.
• A 4 bit shifter is based on multiple levels of small included
multiplexers (which can be transmission gates).
• It include Ex-OR circuit which works as selection control line shifts
the word right of left according to the combination provided.

2. Multilevel Funnel Shifter
 This 4 bit shifter will shifter the bits to the right
side so “Left” will be initially “1” because this
shifter itself shift the data by one bit.
 k0 and k1 bits are the most important bits work as
selection line for the further circuitry and how the
shifting of data occurs by just changing these bits
that calculation is given below.
 Now there are 7 input bits which can be random
bits and that will be converted to the final 5 bits
result for the next multiplexer phase.
 The output of the first phase will work as input of
the second phase and according to the combination
of selection line k0 and k1 the result will be
produced from the given input bits Z0-Z6.

3. EX- OR Circuit
2 input Ex-OR gate schematic circuit with icon view

4. Multiplexer Circuit
2x1 multiplexer schematic circuit with icon view

5. Funnel Shifter

6. Calculation Of Funnel Shifter
1st stage input=1101101
Left=1
k1=0, k0=0 (Case:1)
Mux1 Mux2 Mux3 Mux4 Mux5
0 1 1 0 1
First stage output : 01101
2nd stage
k1=0, k0=0
Mux1 Mux2 Mux3 Mux4
1 1 0 1
Final output: 1101 ( Four bits of input data from first MSB position)

7. Calculation Of Funnel Shifter
1st stage input=1101101
Left=1
k1=0, k0=1 (Case:2)
Mux1 Mux2 Mux3 Mux4 Mux5
1 1 0 1 1
First stage output : 11011
2nd stage
k1=0, k0=1
Mux1 Mux2 Mux3 Mux4
1 0 1 1
Final output: 1011 ( Four bits of input data from second MSB position )

8. Calculation Of Funnel Shifter
1st stage input=1101101
Left=1
k1=1, k0=0 (Case:3)
Mux1 Mux2 Mux3 Mux4 Mux5
0 1 1 0 1
First stage output : 01101
2nd stage
k1=1, k0=0
Mux1 Mux2 Mux3 Mux4
0 1 1 0
Final output: 0110 ( Four bits of input data from third MSB position)

9. Calculation Of Funnel Shifter
1st stage input=1101101
Left=1
k1=1, k0=1 (Case:4)
Mux1 Mux2 Mux3 Mux4 Mux5
1 1 0 1 1
First stage output : 11011
2nd stage
k1=1, k0=1
Mux1 Mux2 Mux3 Mux4
1 1 0 1
Final output: 1101 ( Four bits of input data from fourth MSB position)

10. Funnel Shifter Output

11. Application
• Addition & Subtraction operation in processor
• Logical shift right/left
• Arithmetic shift right/left
• Rotation of bits