Unit DMA

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Description

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To be documented

Constants

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To be documented

Type definitions

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To be documented

Public variables

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To be documented

Function declarations

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Initialization functions

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procedure DMAInit;

Description: To be documented

Note	To be documented

DMA host functions

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function DMAHostStart(DMA:PDMAHost):LongWord;

Description: To be documented

Note	To be documented

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function DMAHostStop(DMA:PDMAHost):LongWord;

Description: To be documented

Note	To be documented

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function DMAHostReset(DMA:PDMAHost):LongWord;

Description: To be documented

Note	To be documented

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function DMAHostProperties(DMA:PDMAHost; Properties:PDMAProperties):LongWord;

Description: To be documented

Note	To be documented

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function DMAHostCreate:PDMAHost;

Description: Create a new DMA entry

Return	Pointer to new DMA entry or nil if DMA could not be created

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function DMAHostCreateEx(Size:LongWord):PDMAHost;

Description: Create a new DMA entry

Size	Size in bytes to allocate for new DMA (Including the DMA entry")
Return	Pointer to new DMA entry or nil if DMA could not be created

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function DMAHostDestroy(DMA:PDMAHost):LongWord;

Description: Destroy an existing DMA entry

Note	To be documented

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function DMAHostRegister(DMA:PDMAHost):LongWord;

Description: Register a new DMA in the DMA host table

Note	To be documented

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function DMAHostDeregister(DMA:PDMAHost):LongWord;

Description: Deregister a DMA from the DMA host table

Note	To be documented

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function DMAHostFind(DMAId:LongWord):PDMAHost;

Description: To be documented

Note	To be documented

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function DMAHostEnumerate(Callback:TDMAEnumerate; Data:Pointer):LongWord;

Description: To be documented

Note	To be documented

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function DMAHostNotification(DMA:PDMAHost; Callback:TDMANotification; Data:Pointer; Notification,Flags:LongWord):LongWord;

Description: To be documented

Note	To be documented

DMA data functions

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function DMADataCount(Data:PDMAData):LongWord;

Description: Return the total number of data blocks in the linked list

Note	To be documented

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function DMADataFlags(Data:PDMAData):LongWord;

Description: Return the combined flags of the data blocks in the linked list

Note	To be documented

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function DMADataMaximum(Data:PDMAData):LongWord;

Description: Return the size of the largest data block in the linked list

Note	To be documented

DMA buffer functions

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function DMABufferAllocate(DMA:PDMAHost; Size:LongWord):Pointer; inline;

Description: Allocate a data buffer for a DMA request

DMA	The DMA host that the request will be sent to
Size	The size of the data buffer to allocate
Return	The newly allocated buffer or nil on failure

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function DMABufferAllocateEx(DMA:PDMAHost; var Size:LongWord):Pointer;

Description: Allocate a data buffer for a DMA request

DMA	The DMA host that the request will be sent to
Size	The size of the data buffer to allocate (Updated on return to actual size)
Return	The newly allocated buffer or nil on failure
Note	This differs from DMABufferAllocate in that it updates the size value to reflect the actual size of the buffer allocated which may be required for some uses

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function DMABufferValidate(DMA:PDMAHost; Buffer:Pointer; Size:LongWord):LongWord;

Description: Validate a data buffer for a DMA request against the DMA host requirements

DMA	The DMA host that the request will be sent to
Buffer	The data buffer to validate
Size	The size of the data buffer
Return	ERROR_SUCCESS on success or another error code on failure (ERROR_NOT_COMPATIBLE if not compatible with host)
Note	Does not check for cache coherency requirements (Shared, Non Cached) only alignment and size. Buffers used as the source of a DMA request do not neccessarily need to meet alignment and size requirements, however buffers used as a destintation must meet these requirements or the caller must take appropriate actions to prevent undesiraable side effects from cache invalidation.

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function DMABufferRelease(Buffer:Pointer):LongWord;

Description: Release a data buffer from a DMA request

Data	The buffer to be released
Return	ERROR_SUCCESS on success or another error code on failure

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