SPRUHZ7K August 2015 – April 2024 AM5706 , AM5708 , AM5716 , AM5718 , AM5718-HIREL
The EDMA controller supports external DMA requests through the dma_evt[4:1] pins (see Table 16-54). A logical channel can be configured to respond to an external synchronization request.
Pin Name | DMA_CROSSBAR Input | Signal Name | I/O(1) | Description | Module Reset Value |
---|---|---|---|---|---|
dma_evt1 | DMA_CROSSBAR_2 | EXT_SYS_DREQ_0 | I | External DMA request 0 (system expansion) | Z |
dma_evt2 | DMA_CROSSBAR_3 | EXT_SYS_DREQ_1 | I | External DMA request 1 (system expansion) | Z |
dma_evt3 | DMA_CROSSBAR_167 | EXT_SYS_DREQ_2 | I | External DMA request 2 (system expansion) | Z |
dma_evt4 | DMA_CROSSBAR_168 | EXT_SYS_DREQ_3 | I | External DMA request 3 (system expansion) | Z |
Figure 16-13 shows an example of how to use the external hardware DMA request pins in the EDMA environment.
An external device can use the external DMA request pins to start a logical channel transfer. The transfer can be a memory-to-memory transfer in which the source memory is in the external device.
By default, the external DMA request signals are not available on external pins after a cold reset. For more information about multiplexing out the two signal lines to pins, refer to Control Module.
All 64 DMA request lines are transition sensitive.