serial stream data to capture in parallel line
 

Hi All,
I am writing VHDL Testbench for Manchester encoding.. i am done with
the simulation and the results on expected output is complex to
analyze or identify what message has been transferred

Description: I am transmitting a message on serial encoded stream
signal TX_OUT; where it consists the message format:<Start Bit>-<5-Bit
Header>-<32-Bit Data[29:1]>-<32-Bit check test word>-<32-Bit O.V.P-
H.W>
Where O.V.P-H.W: Odd Vertical Parity -Hardware Generated
So all these fields are encoded using Manchester format. Here start
Bit is High for 150 ns and Low for 150 ns and the rest of the fields
are High for 50 ns and Low for 50 ns.(Where the rest of the field bits
the Manchester form is : 1->10, 0->01)

I am Writing only Header, data, check test word(which is always having
value:0x0000 0000). After writing VHDL code for this I am having
complexity on Simulation window where I can see TX_OUT will have
serial encoded data with above specified message fields, so to conform
the exact data is transmitted or not I have to analyze the TX_OUT
signal stream which is eating more time and chances to miss any bit
Is there any way to capture the serial encoded stream into any
register or in parallel and observe the message fields in Hexadecimal
or at least Binary of written data.
Please give exposure on this issue.

Thanks

Re: serial stream data to capture in parallel line
 

Hi Sreenivas,
If your design is a transmitter, I would write a model that is a
receiver. Then have that model either write the value received
to a file so you can compare results after the simulation finishes,
or the model can pass the value back up to a higher level in the
testbench so the received value can be compared with the expected
value.

Best,
Jim

BTW, we have a class on August 25-28 on VHDL Testbenches and
Verification that may help you. It is in Beaverton (Portland), OR.
See http://www.synthworks.com/public_vhdl_courses.htm
for details.

Re: serial stream data to capture in parallel line
 

On Aug 17, 9:04*pm, JimLewis <J...@SynthWorks.com> wrote:
> Hi Sreenivas,
> If your design is a transmitter, I would write a model that is a
> receiver. *Then have that model either write the value received
> to a file so you can compare results after the simulation finishes,
> or the model can pass the value back up to a higher level in the
> testbench so the received value can be compared with the expected
> value.
>
> Best,
> Jim
>
> BTW, we have a class on August 25-28 on VHDL Testbenches and
> Verification that may help you. *It is in Beaverton (Portland), OR.
> Seehttp://www.synthworks.com/public_vhdl_courses.htm
> for details.

Hi Jim,
I done simulation for Receiver Model...and i did not get the
explanation of yours...please discuss a bit more on this.
Thanks

Re: serial stream data to capture in parallel line
 

On 18 Aug., 07:43, JSreeniv <sreenivas.jyo...@gmail.com> wrote:
> On Aug 17, 9:04*pm, JimLewis <J...@SynthWorks.com> wrote:
>
> > Hi Sreenivas,
> > If your design is a transmitter, I would write a model that is a
> > receiver. *Then have that model either write the value received
> > to a file so you can compare results after the simulation finishes,
> > or the model can pass the value back up to a higher level in the
> > testbench so the received value can be compared with the expected
> > value.
>
> > Best,
> > Jim
>
> > BTW, we have a class on August 25-28 on VHDL Testbenches and
> > Verification that may help you. *It is in Beaverton (Portland), OR.
> > Seehttp://www.synthworks.com/public_vhdl_courses.htm
> > for details.
>
> Hi Jim,
> I done simulation for Receiver Model...and i did not get the
> explanation of yours...please discuss a bit more on this.
> Thanks
Hi Sreenivas,
Jims approach is kind of a standard procedure for such applications.
For (hopefully) better understanding I recite it in different words:

If your device under test is a transmitter that produces a serial
bitstream, then simply add an instance or a behavioral model (process)
of the corresponding receiver to your testbench. The receiver converts
the serial bitstream back to readable words. Additional processes in
your testbench can automatically check if the received data is the
same as what you fed into the transmitter before. So in a loop you can
very easy check a lot of testpatterns automatically without even
bothering about the waveforms. And when an errpor occurs you have to
take a deeper look at the serial bitstream anyway, but just for the
short period that contains the faulty data.

Have a nice simulation
Eilert