Need some help solving a register pruning issue

[JacquesKleynhans]

I have a pruning issue:

if I have the folowing as output

(293) sda_out <= '0' when reset = '1' else sda when rising_edge(sccbclk_inv);

Iget this warning which screws up my program

W CL169 Pruning Register sda_out_cl_2 sccb.vhd (293) sccb_write.srr (23) 14:45:14 Thu Apr 22 compilerReport

Its in inout declared in the top of my code.

If i do it like this it works but then my output is not offsetted by the sccbclk_inv

sda_out <= sda;

Anyone have any clue ??

 

[vipinlal]

I think you need not worry about this warning.I just googled for pruning registers and I got this link:
**broken link removed**

So the warning you got, may be because the compiler must have noticed that some registers are not actually needed for your logic to work, and it must have optimized the design.

Check your code and see whether these signals - "reset" and "sccbclk_inv" changes.
What I mean is , if reset is always zero in your code, then the compiler will optimize the code into

if (rising_edge(sccbclk_inv)) then
sda_out <= sda;
end if;

--vipin
http://vhdlguru.blogspot.com/