SDMA_ChannelDescriptor Struct Reference
[SDMA Manager]

#include <sdma.h>

Collaboration diagram for SDMA_ChannelDescriptor:

[legend]

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Detailed Description

Descriptor for a channel granted with a SDMA_IOCREQUESTDMA ioctl().

Remarks:

The address of the transferState member is passed down to the SDMAK module during the SDMA_IOCREQUESTDMA ioctl(). The SDMAK module maps this address and queries and writes to it during the completion ISR activity. It is therefore vital that the address of the descriptor passed to SDMA_getChannels() is in persistent memory that is live for the duration of SDMA channel usage.

See also:

SDMA_getChannels()

SDMA_freeChannels()

SDMA_wait()

SDMA_check()

Data Fields
int	chanNum
unsigned int *	addr
SDMA_transferState	transferState

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Field Documentation

int SDMA_ChannelDescriptor::chanNum

channel number

unsigned int* SDMA_ChannelDescriptor::addr

user virtual address of granted DMA registers

struct SDMA_transferState SDMA_ChannelDescriptor::transferState

used for completion checking, whose address is passed down to sdmak kernel driver

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The documentation for this struct was generated from the following file:

• sdma.h

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Copyright 2009, Texas Instruments Incorporated