[YashAnand69]

_transfer passes an 8- or 16-bit width to ConnectionHandler.read, whose argument is a byte count. Firmware returns one or two response bytes followed by an ACK. The oversized read consumes the ACK and fails unpacking instead of completing the transfer.

Read the packed integer's byte size, then consume the ACK separately. This fixes scalar and bulk read/write/transfer operations without changing commands or public APIs. It is separate from #275's firmware-v3 command migration; that patch retains this read length.

Validation:

• Fourteen public SPISlave regressions fail on unchanged main. A byte-oriented response stream checks exact response lengths, ACK boundaries, sequential replies and command framing.
• Available hardware-independent suite: 42 passed (baseline 28); changed line covered and same-subset coverage increases. Configured Black, Flake8, Bandit and pydocstyle checks pass.
• Wheel/source distribution and documentation builds pass. Documentation diagnostics match baseline: five distinct messages, Sphinx counter seven.
• No physical PSLab or full hardware record/playback validation was performed; byte-stream tests exercise the existing protocol contract.

No overlapping response-length fix found in open issues/PRs. Developed and tested with OpenAI Codex assistance.

Summary by Sourcery

Fix SPI transfers to preserve response words and acknowledgements as separate protocol frames.

Bug Fixes:

• Correct SPI response framing by reading the packed response word's byte length and consuming acknowledgements separately.

Tests:

• Add byte-oriented SPI regression coverage for scalar and bulk 8-bit and 16-bit operations, including sequential transfers and command framing.

Summary by CodeRabbit

• Bug Fixes

  • Corrected SPI response handling so 8-bit and 16-bit operations read the expected number of bytes, preventing response data from being misframed.

• Tests

  • Added coverage for single and bulk SPI transfers, reads, and writes, including sequential operations and response framing.

[sourcery-ai]

Reviewer's Guide

Fixes SPI response framing by reading exactly the packed response word size before consuming the ACK, preventing oversized reads from consuming acknowledgement bytes. Adds transport-level regressions covering 8-/16-bit scalar and bulk operations, command framing, and sequential transfers without changing the public API.

Sequence diagram for SPI response framing

sequenceDiagram
    participant SPI as SPISlave
    participant Device as ConnectionHandler
    participant Firmware

    SPI->>Device: send_byte(CP.SPI_HEADER)
    SPI->>Device: send_byte(command)
    SPI->>Device: write(interger_type.pack(data))
    Device->>Firmware: transmit command and packed data
    Firmware-->>Device: response bytes
    Device-->>SPI: read(interger_type.size)
    Device-->>SPI: get_ack()
    SPI-->>SPI: interger_type.unpack(response)

Loading

File-Level Changes

Change	Details	Files
Read SPI response payloads using their packed byte size and consume acknowledgements independently.	Replace the bit-width read length with the packed integer type size. Preserve existing command sequencing and public APIs while fixing scalar and bulk operations.	pslab/bus/spi.py
Add byte-stream regression coverage for response and ACK framing across SPI operations.	Exercise 8-bit and 16-bit scalar and bulk transfer, read, and write paths. Assert exact read sizes, command framing, transmitted payloads, ACK boundaries, and sequential reply preservation.	tests/test_spi_response_framing.py

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[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

• Configuration used: defaults
• Review profile: CHILL
• Plan: Advanced
• Run ID: e79cb181-acc1-4191-81a9-924394fe8fba

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📥 Commits

Reviewing files that changed from the base of the PR and between 08de0d0 and 187c9f5.

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📒 Files selected for processing (2)

• pslab/bus/spi.py
• tests/test_spi_response_framing.py

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Included review availability: This review used your included allowance. Your plan provides up to 4 included reviews per hour; 3 remain after this review.

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📝 Walkthrough

Walkthrough

SPI transfers now read response words using the selected integer type’s byte size. Tests cover 8-bit and 16-bit operations, framing, and response exhaustion.

Changes

SPI response framing

Layer / File(s)	Summary
Transfer response reads and framing tests pslab/bus/spi.py, tests/test_spi_response_framing.py	_transfer reads the selected integer type’s byte size. Tests check read sizes, command framing, results, and response exhaustion for single, bulk, and sequential transfers.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix

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Merge Risk: ⚪ Minimal · up to 187c9

SPI response reads now follow the selected value’s byte width, while acknowledgements remain separate. The supplied test coverage checks framing and response exhaustion across the supported widths; no actionable merge-blocking risk is identified.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage		Docstring coverage is 62.50% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 8 functions across 2 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check		Check skipped - CodeRabbit’s high-level summary is enabled.
Title check		The title clearly and concisely describes the main change: reading SPI response words in bytes.
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.

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[sourcery-ai]

Hey - I've reviewed your changes and they look great!

Sourcery assessment

Approved.

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