search

LattePandaTeam / LattePanda-Mu

All about LattePanda Mu
MIT License
101 stars 6 forks source link

Document which HSIO each PCIe REFCLK pair belongs to #3

Open i509VCB opened 6 months ago

i509VCB commented 6 months ago

While I can largely figure this out from the example schematics. It is not clear from looking at the pinout.

From looking at both carrier schematics REFCLK3 seems to belong to HSIO 1 and 3?

REFCLK HSIO
0 2
1 3
2 8, 9, 10, 11
3 3
4 6
alphaarea commented 6 months ago

I apologize for my previous statement in the Discord group.

There is no binding between REFCLK and PCIe Port. Just make sure every PCIe device has a REFCLK.

REFCLK is only bound to CLKREQ, and REFCLKs with the same number are bound to CLKREQ. The CLKREQ function is disabled by default in the current BIOS. In the next version of BIOS, the option to enable or disable CLKREQ will be opened.