Transport and inertial delay , resolution fns

[kitcha]

i m a new user of vhdl..i would like 2 know the difference between
transport and inertial delay..does the synthesis of these 2 vary??..

i would also like to know the use of RESOLUTION FNS in vhdl..

 

[allanherriman]

i m a new user of vhdl..i would like 2 know the difference between
transport and inertial delay..does the synthesis of these 2 vary??..

Both are ignored for synthesis. I guess that means there is no
difference.

i would also like to know the use of RESOLUTION FNS in vhdl..

If you are a newbie, then I suggest that you shouldn't worry about
these. Resolution functions are used when there are multiple drivers
on a signal. This will only happen (intentionally) when you are
implementing tristate buses, and you will probably want to code these
with std_logic or std_logic_vector. The resolution functions for these
types are already defined for you.

Regards,
Allan

 

[krby_xtrm]

Delays are technology specific, it depends on different devices.
For Resolution functions, you can think of it as two seperate processes
driving the same signal line. for example, one process drives on signal
'c' with a value of 1 and another process drives it with 0 then the
resolved value is 'X' for that case.


Regards,
Krby_XTrM

 

[Charles Bailey]

i m a new user of vhdl..i would like 2 know the difference between
transport and inertial delay..does the synthesis of these 2 vary??..

With inertial delay, the default, a gate or expression behaves kind of
like it had a low pass filter. If a narrow glitch appears on the input
that is narrower than the delay through the gate, then the glitch
doesn't appear at the output.
Transport delay behaves like a transmission line. Whatever is applied
to the input appears at the output after the specified delay.

Charles Bailey