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I2C

In STM32CubeMX, the matching I2C DMA channels and interrupts should be configured.

From the current generator’s perspective, this page mainly covers two generated parameters: the shared buffer size and the DMA enable threshold.

Example​

The last constructor argument is the minimum transfer size required before DMA is enabled.

STM32I2C i2c1(&hi2c1, i2c1_buf, 3);

Configuration File​

After code generation, the following I2C section appears in User/libxr_config.yaml:

I2C:
  i2c1:
    buffer_size: 32
    dma_section: ''
    dma_enable_min_size: 3
  • buffer_size: shared I2C transfer / receive buffer size
  • dma_section: linker section for the generated buffer declaration
  • dma_enable_min_size: minimum transfer byte count to enable DMA

Current generation details:

  • the generator emits one shared buffer per I2C instance, for example i2c1_buf;
  • dma_enable_min_size is currently emitted directly as the last argument of STM32I2C(..., dma_enable_min_size);
  • dma_section only affects where the buffer declaration is placed, and does not change the STM32I2C constructor shape itself.