Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Programming > VHDL > Request Help - Good example of resolution function

Reply
Thread Tools

Request Help - Good example of resolution function

 
 
Daku
Guest
Posts: n/a
 
      01-25-2010
Could some VHDL guru please help me ? Could you please direct me to a
good example of a resolution function for multiple drivers ? I have
tried synthesis on Xilinx ISE 11.1 with Spartan 3 and I am getting
multiple drivers problem. Any hints, suggestions would be of immense
help.
Thank you.
 
Reply With Quote
 
 
 
 
Tricky
Guest
Posts: n/a
 
      01-25-2010
On Jan 25, 6:31*am, Daku <(E-Mail Removed)> wrote:
> Could some VHDL guru please help me ? Could you please direct me to a
> good example of a resolution function for multiple drivers ? I have
> tried synthesis on Xilinx ISE 11.1 with Spartan 3 and I am getting
> multiple drivers problem. Any hints, suggestions would be of immense
> help.
> Thank you.


A resolution function will not solve this problem. What it means is
you have 2 signals driving the same register, which wont work without
a tri-state driver (which internally synthesises to a mux). Id re-
asses your needs and think more about the underlying hardware rather
than functions to "solve" your problem.

As for great examples of resolution functions - look in the
ieee.std_logic_1164 package - its full of all the resolution functions
for the std_logic type.
 
Reply With Quote
 
 
 
 
Dave Pollum
Guest
Posts: n/a
 
      01-25-2010
On Jan 25, 1:31*am, Daku <(E-Mail Removed)> wrote:
> Could some VHDL guru please help me ? Could you please direct me to a
> good example of a resolution function for multiple drivers ? I have
> tried synthesis on Xilinx ISE 11.1 with Spartan 3 and I am getting
> multiple drivers problem. Any hints, suggestions would be of immense
> help.
> Thank you.


If you have multiple processes driving the same signal, you will get
this error.
-Dave Pollum
 
Reply With Quote
 
Kenn Heinrich
Guest
Posts: n/a
 
      01-25-2010
Daku <(E-Mail Removed)> writes:

> Could some VHDL guru please help me ? Could you please direct me to a
> good example of a resolution function for multiple drivers ? I have
> tried synthesis on Xilinx ISE 11.1 with Spartan 3 and I am getting
> multiple drivers problem. Any hints, suggestions would be of immense
> help.
> Thank you.


In *theory* this works - it's a well defined solution in
simulation. The problem is that in *practice* the synthesizers of the
world don't bother to try to implement the behaviour of a resolution
function. They typically just give you an error that multiple drivers
exist on the same signal.

You'll have to restructure your design instead.

- Kenn
 
Reply With Quote
 
Mike Treseler
Guest
Posts: n/a
 
      01-25-2010
Daku wrote:
> Could some VHDL guru please help me ? Could you please direct me to a
> good example of a resolution function for multiple drivers ?


The standard types already have resolution functions.
That is not your problem.

-- Mike Treseler
 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Help: Function Overloading Resolution, Which Function? coolpint@yahoo.co.uk C++ 6 03-27-2006 07:04 PM
How do you change the Modelsim Cursor Resolution (not simulation resolution) Andrew FPGA VHDL 0 09-26-2005 04:05 AM
Resolution resolution Simon Digital Photography 4 02-27-2004 01:53 PM
Re: Accessing Request.InputStream / Request.BinaryRead *as the request is occuring*: How??? Brian Birtle ASP .Net 2 10-16-2003 02:11 PM
ISO Resolution Chart and Printing Resolution Jack Yeazel Digital Photography 0 08-11-2003 11:19 PM



Advertisments