Debugging SPI communication issues

Upendra Kumar Upendra Kumar

Upendra Kumar

Automotive Software Engineer|Autosar|BSW|RTE|SWC|Memory Stack|Com Stack|CddSbc|Stepper Motor Driver|Bare-Metal Diriver|Integration MATLAB|Simulink|State flow|Embedded C

发布日期: 2025年3月22日
+ 关注

Case 1: Master can't able to produce clock and data?

? Root Causes:

  • Master mode not enabled in control register.
  • SPI peripheral clock not enabled in RCC.
  • MOSI/SCLK GPIO pins not set to alternate function mode.
  • Other code overriding SPI configuration in complex projects.

Tip: Dump & inspect all SPI-related register values just before transmission.

Case 2: Master is sending data but slave is not receiving data?

? Root Causes:

  • NSS (Slave Select) not pulled low.
  • Slave’s SPI pins in Hi-Z state.
  • GPIO alternate function mode misconfigured.
  • NVIC interrupt not enabled for the slave if it uses interrupts.

Case 3: SPI Interrupts are not triggering?

? Root Causes:

  • TXEIE or RXNEIE not set in SPI CR2 register.
  • NVIC interrupt for SPI peripheral not enabled.
  • Forgetting to call NVIC_EnableIRQ().

Checklist: SPI_CR2 ? NVIC configuration ? ISR registration

Case 4: Master is producing right data but slave is receiving the different data?

? Root Causes:

  • High SPI clock (e.g., > 4MHz) with long interconnecting wires
  • Signal integrity issues due to delay/skew.
  • Must match same configuration at Spi Master and Spi Slave

Spi Modes

  • Fix: Use shorter wires or reduce SPI speed (e.g., 500KHz).

Rupesh Pilania

IoT Lead

1 天前

SPI Mode is most useful I found. I struggled for 2-3 days to initialize SD card in SPI mode due to mode differences for FAT file implemention using pic microcontrollers during 2012 That time SDIO interface was not available for pic microcontrollers, even today it is not available. Some PIC32 microcontrollers (MIPS-based) and SAM microcontrollers (ARM Cortex-based, acquired from Atmel) do offer SDHC or SDIO support.

赞
回复
1 次回应

要查看或添加评论，请登录

Upendra Kumar的更多文章

  • Understanding Data Watchpoints in Embedded Debugging
    2025年3月18日

    Understanding Data Watchpoints in Embedded Debugging

    In embedded systems debugging, Data Watchpoints are a powerful tool for tracking variable modifications in real-time…

  • System Basis Chips (SBCs)
    2025年3月11日

    System Basis Chips (SBCs)

    What is an SBC? SBC (System Basis Chip) is an integrated chip used in automotive Electronic Control Units (ECUs). It…

  • NVRAM Manager in AUTOSAR
    2025年2月3日

    NVRAM Manager in AUTOSAR

    1. Basic Working Principle : Consider fig.

  • AUTOSAR DCM Module
    2025年1月29日

    AUTOSAR DCM Module

    1. AUTOSAR DCM Module : In case of vehicle diagnostics, diagnostic tester tool sends a diagnostic request to ECU and…

    1 条评论
  • Autosar Com Stack
    2024年9月25日

    Autosar Com Stack

    1. SWC (Software Component) ?The SWC is an application-level module that generates or receives data, which needs to be…

  • Memory Organization
    2024年9月25日

    Memory Organization

    1. 32-bit Address Space: - The ARM processor uses a 32-bit address, meaning it can address up to 4 GB of memory.

    1 条评论