Alt_avalon_sgdma_construct_mem_to_mem_desc(), Alt_avalon_sgdma_construct_mem_to_mem_desc() -19 – Altera Embedded Peripherals IP User Manual
Page 210
Thread-safe:
No.
Available from
ISR:
Not recommended.
Include:
<altera_avalon_sgdma.h>, <altera_avalon_sgdma_descriptor.h>, <altera_
avalon_sgdma_regs.h>
Parameters:
*dev—a pointer to an SG-DMA device structure.
*desc—a pointer to a single, constructed descriptor. The descriptor must have its
“next” descriptor field initialized either to a non-ready descriptor, or to the next
descriptor in the chain.
Returns:
Returns the contents of the status register.
Description:
Sends a fully formed descriptor or list of descriptors to the SG-DMA controller
for transfer. This function blocks both before transfer, if the SG-DMA controller
is busy, and until the requested transfer has completed. If an error is detected
during the transfer, it is abandoned and the controller’s status register contents
are returned to the caller. Additional error information is available in the status
bits of each descriptor that the SG-DMA processed. The user application
searches through the descriptor or list of descriptors to gather specific error
information. The run bit is cleared before the begining of the transfer and is set
to 1 to restart a new descriptor chain.
alt_avalon_sgdma_construct_mem_to_mem_desc()
Prototype:
void alt_avalon_sgdma_construct_mem_to_mem_desc(alt_sgdma_descriptor
*desc, alt_sgdma_descriptor *next, alt_u32 *read_addr, alt_u32 *write_addr, alt_
u16 length, int read_fixed, int write_fixed)
Thread-safe:
Yes.
Available from
ISR:
Yes.
Include:
<altera_avalon_sgdma.h>, <altera_avalon_sgdma_descriptor.h>, <altera_
avalon_sgdma_regs.h>
Parameters:
*desc—a pointer to the descriptor being constructed.
*next—a pointer to the “next” descriptor. This does not need to be a complete or
functional descriptor, but must be properly allocated.
*read_addr—the first read address for the SG-DMA transfer.
*write_addr—the first write address for the SG-DMA transfer.
length—the number of bytes for the transfer.
read_fixed—if non-zero, the SG-DMA reads from a fixed address.
write_fixed—if non-zero, the SG-DMA writes to a fixed address.
Returns:
void
UG-01085
2014.24.07
alt_avalon_sgdma_construct_mem_to_mem_desc()
21-19
Scatter-Gather DMA Controller Core
Altera Corporation