General • Re: DMA and shared IRQ....

Code:

// DMA channels ids for 6809 bus interface readsextern uint8_t ReadDMA1;extern uint8_t ReadDMA2;// DMA channels ids for 6809 bus interface writesextern uint8_t WriteDMA1;extern uint8_t WriteDMA2;// Zero based interrupt numbers to use for each DMA channel, // RP2040 has 2 0..1, RP2350 has 4 0..3#define ReadDMA_IRQ         1#define WriteDMA_IRQ        2#define ClearReadIRQ()      dma_hw->irq_ctrl[ReadDMA_IRQ].ints = 1u << ReadDMA2 #define ClearWriteIRQ()     dma_hw->irq_ctrl[WriteDMA_IRQ].ints = 1u << WriteDMA2 #define ReadIRQFlag         (dma_hw->irq_ctrl[ReadDMA_IRQ].ints & 1u << ReadDMA2)#define WriteIRQFlag        (dma_hw->irq_ctrl[WriteDMA_IRQ].ints & 1u << WriteDMA2)

Code:

    // Setup dma interrupt handler to run after the byte has been read.                          dma_irqn_set_channel_enabled(ReadDMA_IRQ, ReadDMA2, true);    irq_set_exclusive_handler(ReadDMA_IRQ+DMA_IRQ_0, ReadDMA_Handler);    irq_set_enabled(ReadDMA_IRQ+DMA_IRQ_0, true);