16x1 Mux Barrel Shifter

[ss_engg]

hi
Plz help me to construct a 16x1 Mux barrel Shifter code in verilog.
The given data is that we want to move the output data
Shift left
Shift Right
Rotate Left
Rotate Right

 

[lostinxlation]

let's see your code and we may help you.

 

[ss_engg]

Code of barrel shifter:

Type 00 for left Shift
Type 01 for right Shift
Type 10 for left Rotate
Type 11 for right Rotate

Code:

module barrel_shifter(data, type, amount, out);
input [3:0] data;
input [1:0] type;
input [1:0] amount;
output [3:0] out;
endmodule

module barrel(u, y, t, out);
input [3:0] u; %data
input [1:0] y; %type
input [1:0] t; %amount
output [3:0] out;
assign zero=(0);
MUX0 m1(u[0],zero,zero,zero,a[0],a[1],a[2],a[3],a[0],a[3],a[2],a[1],a[0],a[1],a[2],a[3],t[0],t[1], y[0],y[1],out[0]);
MUX1 m2(u[1],u[0],zero,zero,u[1],u[2],u[3],zero,u[1],u[0],u[3],u[2],u[1],u[2],u[3],u[0],u[0],u[1], y[0],y[1],out[1]);
MUX2 m3(u[2],u[1],u[0],zero,u[2],u[3],zero,zero,u[2],u[1],u[0],u[3],u[2],u[3],u[0],u[1],u[0],u[1], y[0],y[1],out[2]);
MUX3 m4(u[3],u[2],u[1],u[0],u[3],zero,zero,zero,u[3],u[2],u[1],u[0],u[3],u[0],u[1],u[2],t[0],t[1], y[0],y[1],out[3]);
endmodule

 

[lostinxlation]

I didn't check all the 4 bit output, but at least, out[0] in your code is correct and I think the line of your thinking is right. There are some typo where a[0], a[1].... should be u[0], u[1]....

 

[ss_engg]

well i don't understand the input 16 bit combinations. how it would be settle there??

 

[lostinxlation]

y=00 for left Shift
y=01 for right Shift
y=10 for left Rotate
y=11 for right Rotate

t[1:0] shft amount

Since it seems a homework or some sort, I'll give you only a hint.

y[1:0] and t[1:0] give you 16 different types of shift operation. Each shift operation is assigned to one of the 16 inputs of MUX16.

for example, y=01, and t=10, it's a right-shift by 2. By this operation, out[0] gets u[2], out[1] gets u[3] and out[3:2] gets zeros. Make a truth table to all the 16 different patterns for all the 4 bit outputs.

 

[ss_engg]

We create it by using 4 no of 16x1 Muses.. if we apply one operation e.g shift right than apply 16 bit combinations to all 4 16x1 muses..?????/
and what is meant by u[0], u[1] etc????

---------- Post added at 07:08 ---------- Previous post was at 06:18 ----------

and how the bits shifted or rotated??

 

[lostinxlation]

We create it by using 4 no of 16x1 Muses.. if we apply one operation e.g shift right than apply 16 bit combinations to all 4 16x1 muses..?????/

i don't get what you mean.

and what is meant by u[0], u[1] etc????

huh ? did you not make that code you posted ?

and how the bits shifted or rotated??

Read a digital design book.

 

[ss_engg]

sir we connected 4 Mux of 16x1 and then create a barrel shifter..
Actually i want to confirm it that if we use a[3] what is meant by that??/
is it a third bit or anything else?

 

[lostinxlation]

Good luck.

 

[ss_engg]

Well have you any idea about anything more???

 

[lostinxlation]

I may help you if you show some more effort rather than keep asking the questions for every tiny things that you can easily find the answer for by a simple analysis of the code.
Till then, good luck.

 

[ss_engg]

Well Sir i completed the barrel shifter code.. Thankyou very much for the Help...
well 1 thing can you know any site where we get the Xilinx ISE 8.2i software..

 

[mrflibble]

Probably in the archives on xilinx.com? As in download ISE 13, and then go to older version...

 

[gurmeet kaur]

plz help me in constructing 16-bit barrel shifter using mux.................

 

[mrflibble]

Step 1: google
Step 2: do homework

Come on, at least pretend to be doing a little effort. If you are stuck, show the code you have so far so people can help you. If you don't have any code yet, goto 1.