sample

Hello group,

In one of the previous threads, I had pointed out to page 15 at
http://www.wolfsonmicro.com/uploads/.../en/WM8731.pdf
documentation which discusses a CODEC. Now, I need to write a VHDL
code to simulate this but was wondering if there is an online example
or something that can give me a lead to follow.

Thanks.

Amit

On Fri, 21 Mar 2008 00:45:04 -0700 (PDT), Amit wrote:

>In one of the previous threads, I had pointed out to page 15 at
>http://www.wolfsonmicro.com/uploads/.../en/WM8731.pdf
>documentation which discusses a CODEC. Now, I need to write a VHDL
>code to simulate this but was wondering if there is an online example
>or something that can give me a lead to follow.

As usual when thinking about simulation models of existing devices,
the big question is: what parts of the device's behaviour do you
wish to simulate?

For many digital verification scenarios, it's sufficient to
mimic the digital behaviour (timing, register activity) of
the digital interfaces, providing dummy data to represent
the analogue values flowing through those digital interfaces.
You'll need to know about the data format (AC96 or whatever)
that's used to serialise the data, but that's not too hard.

If you want to link the thing a little more accurately to the
simulated analogue domain, then you need to model behaviour
on the analogue pins too. There are various ways to do this
in digital VHDL, none entirely satisfactory, but modelling
a DAC or ADC's conversion is easy - just take a "real" number
representing the analogue value and type-convert it to the
appropriate number of digital bits.

If you plan to simulate all the rather sophisticated filtering
that's going on inside the device, you have a tough DSP
challenge ahead of you.

Tell us what you really need and perhaps we can find some
useful suggestions, or examples of the kind of behavioural
model that you will require.
--
Jonathan Bromley, Consultant

DOULOS - Developing Design Know-how
VHDL * Verilog * SystemC * e * Perl * Tcl/Tk * Project Services

Doulos Ltd., 22 Market Place, Ringwood, BH24 1AW, UK

http://www.MYCOMPANY.com

The contents of this message may contain personal views which
are not the views of Doulos Ltd., unless specifically stated.

Jonathan Bromley

Amit wrote:
>
> Hello group,
>
> In one of the previous threads, I had pointed out to page 15 at
> http://www.wolfsonmicro.com/uploads/.../en/WM8731.pdf
> documentation which discusses a CODEC. Now, I need to write a VHDL
> code to simulate this but was wondering if there is an online example
> or something that can give me a lead to follow.
>
> Thanks.

Amit,

For general information about component modeling, go to
www.FreeModelFoundry.com. They do not have a model of theCODEC you are
using but they do have lots of other models to serve as examples.

Rick

Rick

On Mar 21, 2:30 am, Jonathan Bromley <jonathan.brom...@MYCOMPANY.com>
wrote:
> On Fri, 21 Mar 2008 00:45:04 -0700 (PDT), Amit wrote:
> >In one of the previous threads, I had pointed out to page 15 at
> >http://www.wolfsonmicro.com/uploads/.../en/WM8731.pdf
> >documentation which discusses a CODEC. Now, I need to write a VHDL
> >code to simulate this but was wondering if there is an online example
> >or something that can give me a lead to follow.
>
> As usual when thinking about simulation models of existing devices,
> the big question is: what parts of the device's behaviour do you
> wish to simulate?
>
> For many digital verification scenarios, it's sufficient to
> mimic the digital behaviour (timing, register activity) of
> the digital interfaces, providing dummy data to represent
> the analogue values flowing through those digital interfaces.
> You'll need to know about the data format (AC96 or whatever)
> that's used to serialise the data, but that's not too hard.
>
> If you want to link the thing a little more accurately to the
> simulated analogue domain, then you need to model behaviour
> on the analogue pins too. There are various ways to do this
> in digital VHDL, none entirely satisfactory, but modelling
> a DAC or ADC's conversion is easy - just take a "real" number
> representing the analogue value and type-convert it to the
> appropriate number of digital bits.
>
> If you plan to simulate all the rather sophisticated filtering
> that's going on inside the device, you have a tough DSP
> challenge ahead of you.
>
> Tell us what you really need and perhaps we can find some
> useful suggestions, or examples of the kind of behavioural
> model that you will require.
> --
> Jonathan Bromley, Consultant
>
> DOULOS - Developing Design Know-how
> VHDL * Verilog * SystemC * e * Perl * Tcl/Tk * Project Services
>
> Doulos Ltd., 22 Market Place, Ringwood, BH24 1AW, UK
> jonathan.brom...@MYCOMPANY.comhttp://www.MYCOMPANY.com
>
> The contents of this message may contain personal views which
> are not the views of Doulos Ltd., unless specifically stated.


Hello Jonathan,

Thanks for your time and explaining it. One thing is that in this
phase of the project I need to simulate it base on timing on page 15.
Please correct me if I'm wrong. I think I have to implement it either
counter or FSM but I'm confused and not sure to start it.

1) should I use the exact timing values?
2) do you suggest counter or fsm?


Thanks.

Amit

On Mar 22, 11:59 am, Rick <fmfoun...@sbcglobal.net> wrote:
> Amit wrote:
>
> > Hello group,
>
> > In one of the previous threads, I had pointed out to page 15 at
> >http://www.wolfsonmicro.com/uploads/.../en/WM8731.pdf
> > documentation which discusses a CODEC. Now, I need to write a VHDL
> > code to simulate this but was wondering if there is an online example
> > or something that can give me a lead to follow.
>
> > Thanks.
>
> Amit,
>
> For general information about component modeling, go towww.FreeModelFoundry.com. They do not have a model of theCODEC you are
> using but they do have lots of other models to serve as examples.
>
> Rick


Rick thanks you so much. It was big help. Of course couldn't find any
CODEC example but there are so many helpful samples.

Thank you.

Amit