Modular SGDMA - Streaming to Memory Mapped Random first write.

I've attached the Nios code I was using.

In your main c file,# include "ScatterGatherController.h", then declare a global variable as:

PSGC_CONTROLREGS const dma_csr_base = (PSGC_CONTROLREGS)(<Base address of the CSR, e.g. from system.h>)

PSGC_DESCRIPTOR_FORMAT const dma_descriptor_base = (PSGC_DESCRIPTOR_FORMAT)(<Base address of the descriptors, e.g. from system.h>)

You can then pass those pointers to the functions in the .h/.c files as the 'base' variable.

You'll need to initialise the controller. This can be done using sgc_initialiser(), sgc_enabler(), and sgc_enableDispatcher(). See the .h file for the function declarations.

If you want to send a descriptor, you can create the following:

SGC_DESCRIPTOR_FORMAT descriptor;

descriptor.write_address = ...;

descriptor.read_address = ...;

descriptor.transfer_length = ...;

descriptor.control.bits.<some field, see .h> = ...;

sgc_issue_descriptor(dma_descriptor_base, &descriptor)

Hope the SGDMA controller proves more reliable for you than it did for me.