Direct memory access controller (DMA) RM0402
216/1163 RM0402 Rev 6
If the TEIFx or the FEIFx flag is set due to incompatibility between burst size and FIFO
threshold level, the faulty stream is automatically disabled through a hardware clear of its
EN bit in the corresponding stream configuration register (DMA_SxCR).
If the DMEIFx or the FEIFx flag is set due to an overrun or underrun condition, the faulty
stream is not automatically disabled and it is up to the software to disable or not the stream
by resetting the EN bit in the DMA_SxCR register. This is because there is no data loss
when this kind of errors occur.
When the stream's error interrupt flag (TEIF, FEIF, DMEIF) in the DMA_LISR or DMA_HISR
register is set, an interrupt is generated if the corresponding interrupt enable bit (TEIE,
FEIE, DMIE) in the DMA_SxCR or DMA_SxFCR register is set.
Note: When a FIFO overrun or underrun condition occurs, the data is not lost because the
peripheral request is not acknowledged by the stream until the overrun or underrun
condition is cleared. If this acknowledge takes too much time, the peripheral itself may
detect an overrun or underrun condition of its internal buffer and data might be lost.
9.4 DMA interrupts
For each DMA stream, an interrupt can be produced on the following events:
• Half-transfer reached
• Transfer complete
• Transfer error
• FIFO error (overrun, underrun or FIFO level error)
• Direct mode error
Separate interrupt enable control bits are available for flexibility as shown in the table below.
Note: Before setting an enable control bit EN = 1, the corresponding event flag must be cleared,
otherwise an interrupt is immediately generated.
Table 38. DMA interrupt requests
Interrupt event Event flag Enable control bit
Half-transfer HTIF HTIE
Transfer complete TCIF TCIE
Transfer error TEIF TEIE
FIFO overrun/underrun FEIF FEIE
Direct mode error DMEIF DMEIE
To Next Page
Loading...
Need help?
General
