embedded protocol_error ai_generated true

SPI: CRC error on receive, calculated 0x1A2B expected 0x3C4D

ID: embedded/spi-crc-error-receive-mode

Also available as: JSON · Markdown · 中文
88%Fix Rate
86%Confidence
1Evidence
2023-09-05First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
STM32Cube_FW_G4 V1.5.0 active — — —
SPI HAL V1.4.0 active — — —

Root Cause

SPI CRC mismatch due to noise on lines, incorrect polynomial configuration, or data length mismatch between master and slave.

generic

中文

SPI CRC 不匹配因线路噪声、多项式配置错误或主从设备数据长度不一致。

Official Documentation

https://www.st.com/resource/en/reference_manual/dm00314099.pdf

Workarounds

  1. 90% success Verify SPI CRC polynomial matches between master and slave: `SPI_CR1_CRCPOLY` register must be identical. Use `SPI_CR1_CRCEN` to enable CRC. 
    Verify SPI CRC polynomial matches between master and slave: `SPI_CR1_CRCPOLY` register must be identical. Use `SPI_CR1_CRCEN` to enable CRC.
  2. 85% success Add software CRC check after each transaction as fallback: compute CRC16-CCITT on received data and compare. 
    Add software CRC check after each transaction as fallback: compute CRC16-CCITT on received data and compare.
  3. 80% success Reduce SPI clock to below 5 MHz to improve signal integrity on noisy lines. 
    Reduce SPI clock to below 5 MHz to improve signal integrity on noisy lines.

中文步骤

  1. 验证主从设备的 SPI CRC 多项式一致：`SPI_CR1_CRCPOLY` 寄存器必须相同。使用 `SPI_CR1_CRCEN` 使能 CRC。
  2. 每次传输后添加软件 CRC 检查作为后备：计算接收数据的 CRC16-CCITT 并比较。
  3. 将 SPI 时钟降至 5 MHz 以下以改善嘈杂线路上的信号完整性。

Dead Ends

Common approaches that don't work:

  1. 80% fail

    Increasing SPI clock speed exacerbates signal integrity issues, making CRC errors more frequent.

  2. 50% fail

    Reseating cables does not fix incorrect polynomial settings in software.