update timescale

[IstvanZsSzekely]

PR Description

Updated timeunit and timeprecision to 1ns / 1ps and removed the `timescale directive from the simulation files to avoid confusion and weird simulation behavior.
Updated logger to print ps time as fraction to ns for more accurate logging. The logging message timestamps will be more precise.
Updated test programs to support new time scaling. Since the old format was ns/ps, the current testbenches that don't have time fraction specified for delays (# 10 for example), will automatically use the new ps/fs format, and because of it, they wouldn't work correctly. Instead of waiting for 10 ns, they would wait for 10 ps.

PR Type

• Bug fix (change that fixes an issue)
• New feature (change that adds new functionality)
• New test (change that adds new test program and/or testbench)
• Breaking change (has dependencies in other repositories/testbenches)
• Documentation (change that adds or modifies documentation)

PR Checklist

• I have followed the code style guidelines
• I have performed a self-review of changes
• I have ran all testbenches affected by this PR
• I have commented my code, at least hard-to-understand parts
• I have signed off all commits from this PR
• I have updated the documentation (wiki pages, ReadMe files, Copyright etc)
• I have not introduced new Warnings/Errors on compilation/elaboration/simulation
• I have set the verbosity level to none for the test program

[LBFFilho]

It looks good, but it fails spi_engine's test_sleep_delay. This is caused by the axi_clkgen now needing a lot more time before it generates a valid output clock, and test_sleep_delay doesn't wait the adequate time.

This was the axi_clkgen time before the PR:

This is after the PR:

Both pictures from test_program, which actually passes, because test_sleep_delay is not patient enough for us to see the clock.

I suppose other time-sensitive tests can have similar problems.

I guess a simple fix is just to make it wait more (or better yet make it wait for a specific condition ie. cmd_ready), but I think it's probably better to also fix the clock generator extra delay.

[IstvanZsSzekely]

It looks good, but it fails spi_engine's test_sleep_delay. This is caused by the axi_clkgen now needing a lot more time before it generates a valid output clock, and test_sleep_delay doesn't wait the adequate time.

This was the axi_clkgen time before the PR:

This is after the PR:

Both pictures from test_program, which actually passes, because test_sleep_delay is not patient enough for us to see the clock.

I suppose other time-sensitive tests can have similar problems.

I guess a simple fix is just to make it wait more (or better yet make it wait for a specific condition ie. cmd_ready), but I think it's probably better to also fix the clock generator extra delay.

Thank you for letting me know! I'll look into it and come up with a solution.