Forum Discussion
MAX10 Signal propagation
I have a mux
F_LPTG_OUT(0) <= F_LPTG_IN(0) when (sel(0) = '1') else cpu_out(0);What signal propagation time will be from the input to the output?
7 Replies
- KennyT_altera
Super Contributor
basically, you have a mux which means there will be 3 input to one output. we calculate the delay base on register to register in time quest.
You should be able to pull out the delay from the time quest for the delay that you have.
- EEren
Occasional Contributor
I go to Time Quest -> Custom Reports -> Report Path. Fill From and To.
report_path -from [get_ports {F_LPTG_IN[0]}] -to [get_ports {F_LPTG_OUT
[0]}] -npaths 1 -panel_name {Report Path} -multi_corner
I get - Report Path: No paths were found
- EEren
Occasional Contributor
OK. I did it. I got a delay from input to output 9.378 nanosec. It's awful. I need 2-3 nanosec. What can I use faster then mux?
- KennyT_altera
Super Contributor
As mention, timequest report path from reg to reg. You need to see what reg to reg on the path that you interest and report from there. In the btw the register, you have to manually add in the delay to sum out the delay of your path.
- EEren
Occasional Contributor
I have fast switching signals. Maxsimum delay 3 nanosec. I got 9.378. What can I use to commutate inputs to output faster?
- a_x_h_75
Contributor
If you need it to be quicker, and that's the only way to design it, then you'll need a faster speed grade device or, more likely, a faster device family. MAX 10 isn't particularly fast.
Where are these signals coming from? I'm assuming they're from device pins...
Cheers,
Alex
- sstrell
Super Contributor
If you are looking at a report from an input of the device all the way to an output, you're looking at the total delay through the entire device, so of course it might be large. Can you clarify exactly what reporting command you used that worked and also where the registers are in this design?