Nios® V Processor Software Developer Handbook

ID 743810
Date 10/02/2023
Public

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Document Table of Contents

13.1.1.19. alt_dma_rxchan_prepare()

Prototype

int alt_dma_rxchan_prepare (alt_dma_rxchan dma, 
 void* data, 
 alt_u32 length, 
 alt_rxchan_done* done, 
 void* handle)

Commonly Called By

C/C++ programs

Device drivers

Thread-safe

See description.

Available from ISR

See description.

Include

<sys/alt_dma.h>

Description

The alt_dma_rxchan_prepare() posts a receive request to a DMA receive channel. The input arguments are: dma, the channel to use; data, a pointer to the location that data is to be received to; length, the maximum length of the data to receive in bytes; done, callback function that is called after the data is received; handle, an opaque value passed to done.

Whether this function is thread-safe, or can be called from an ISR, depends on the underlying device driver. In general it safest to assume that it is not thread-safe.

Return

The return value is zero upon success. A negative return value indicates that the request cannot be posted.