oxidecomputer / oxidecomputer/quartz

Extra sclk inserted before a STOP by i2c link layer

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Dominant language
VHDL
Stars
22
Forks
2
Avg merge
9h 38m
Merged PRs (30d)
1

Description

Since we've NACK'd on reads or are doing writes, this is benign in that it causes no bad behavior but is incorrect.

Image

Red marker is the ACK phase. Green marker is the CLK high period where the STOP should be generated but instead it is generated at the next clock.

Contributor guide

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First steps

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  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by tracing the I2C link layer's STOP generation and compare its behavior with the attached waveform, focusing on the ACK phase and the extra clock before STOP. Done means the STOP is generated during the indicated clock-high period rather than on the next clock, without inserting an extra SCLK.

Written by the indexing model from the issue text.

Assessment

Domain
embedded-iot
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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