chili-chips-ba / openCologne

Spicing up the first and only EU FPGA chip with a flashy new board, loaded with a suite of engaging demos and examples. https://www.chili-chips.xyz/open-cologne
https://nlnet.nl/project/openCologne
BSD 3-Clause "New" or "Revised" License
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P_R '-om' default is set agressively and does not match Olimex default #35

Closed chili-chips-ba closed 1 month ago

chili-chips-ba commented 2 months ago

@pu-cc what's the rationale behind setting the -om P_R default to the highest possible supply voltage? Note that Olimex board defaults to midpoint. That's a recipe for problems.

Please, help us also understand the implications of the P_R -tm option, as well as its interplay with the -om.


CologneChip P_R Default Olimex-VDD_CORE_SET-Jumper Olimex-Default

pu-cc commented 2 months ago

what's the rationale behind setting the -om P_R default to the highest possible supply voltage?

It gives a good understanding what the design can achieve in best case (1.1V) and the worst conditions.

Please, help us also understand the implications of the P_R -tm option, as well as its interplay with the -om.

With -om, you specify the core voltage:

In addition, the corner/conditions -tm can be specified, as this also has an effect on the timing:

As far as i know, tools usually output their timings as "worst conditions".