preet schrieb:

> I have written the code for my encoder below. It is synthesizable and has no errors.

This is good, but does not prove too much.

> What i want to do is after programming the FPGA(Spartan3 starter kit), I want to check the results from the harware.
> 
> Means using LEDs for 3 bit output and switch for the input.

This might be a nice test (or better call it play around), but a 
simulation is much better and does show much more. So your "test" isn't 
a real test, it has no practical relevance.

> My code also contains the clock signal.
> 
> IF i lock one switch to Clock and then toggle it's not working and i think it won't.

You can't use a normal switch to supply a clock to a digital circuit, 
especially not a modern FPGA. The switch WILL bounce and produce 
multiple pulses. A debouncing is necessary, either by hardware 
(RC-filter + schmitt trigger) or software (logic inside the FPGA)

> I want to test this code on hardware.
> 
> Some one suggested Using Picoblaze, RS232,UART connection.
> 
> I really have no clue of how to do it.

Looks like you just starting to get into the digital/FPGA business. 
Start small. Get a  simpler circuit thant a Viterby decoder. Get a 
feeling for simulation and testing in hardware, understand the 
difference and the idea behind the different ways of testing.
For instance, build a simple 4 bit counter. Do a clean simulation. 
Implement it in hardware. Test it in hardware (use a switch debouncer).
Then go on to the Viterby.

> Where to get picoblaze, how to program it to take input from RS232,
 > where to get UART models. And how will i be writing the text in 
hyperterminal
 > to send the data through this port.Will i be actually toggling the
 > switch which i have locked for input.

Picoblaze can be found on the Xilinx website, look for xapp213.

> I badly need help on this.

I think you need to understand some basic concepts first.

Regards
Falk

Thanks so much to all who replied to my previous messages I appreciate your concern.

Please help me on this.

I have written the code for my encoder below. It is synthesizable and has no errors.

What i want to do is after programming the FPGA(Spartan3 starter kit), I want to check the results from the harware.

Means using LEDs for 3 bit output and switch for the input.

My code also contains the clock signal.

IF i lock one switch to Clock and then toggle it's not working and i think it won't.

I want to test this code on hardware.

Some one suggested Using Picoblaze, RS232,UART connection.

I really have no clue of how to do it.

Where to get picoblaze, how to program it to take input from RS232, where to get UART models. And how will i be writing the text in hyperterminal to send the data through this port.Will i be actually toggling the switch which i have locked for input.

I badly need help on this.

thanks and regards

Code:

module encoder(outp,clk,res,inp); input clk,res,inp; outp[2:0] outp; reg [4:0]ff;

always@(posedge clk) begin

if(res) ff[4:0]<=5'b0; else

begin ff[3:0]<=ff[4:1]; ff[4]<=inp; end

end

assign outp[0]=ff[4]^ff[2]^ff[0]; assign outp[1]=ff[4]^ff[3]^ff[1]^ff[0]; assign oupt[2]=ff[4]^ff[3]^ff[2]^ff[1]^ff[0]; endmodule