Intel PCI-7200 User Manual

Page 49

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C/C++ Libraries

• 39

5.14 _7200_Free_DMA_Mem

@ Description

Release the system DMA memory under Windows 95/98 environment. This
function is only available in Windows 95/98 version.

@ Syntax

Visual C++ (Windows 95)

int W_7200_Free_DMA_Mem (U32 handle)

Visual Basic (Windows 95)

W_7200_Free_DMA_Mem (ByVal handle As Long ) As Long

@ Argument

handle:

The handle of system DMA memory to release.

@ Return Code

ERR_NoError

5.15 _7200_Alloc_DBDMA_Mem

@ Description

Contact Windows 95/98 system to allocate a block of contiguous memory as
circular buffer for double-buffered DMA DI transfer. This function is only
available in Windows 95/98 version. For double-buffered transfer principle,
please refer to Section 6 “Double Buffered Mode Principle”.

@ Syntax

Visual C++ (Windows 95)

int W_7200_Alloc_DBDMA_Mem (U32 *buff,U32 *handle, U32

buf_size, U32 *actual_size)

Visual Basic (Windows 95)

W_7200_Alloc_DBDMA_Mem (buff As Long, handle As Long, ByVal

buf_size As Long, actual_size As Long) As Long

@ Argument

buff : There is a dummy buffer attached to the DMA memory this function
will allocate. But this buffer need to have size equal to or more than buf_size
bytes.
handle:

The handle of system DMA memory returned from system.

Use this handle in _7200_DI_DMA_Start.
buf_size:

Bytes to allocate. This is the half size of circular buffer in byte.

That is, this is the size of each half buffer in byte.
actual_size: The actual DMA memory size system allocate for each half
buffer. If system is not able to get a block of contiguous memory of specified
buf_size, it will allocate a block of memory as large as it can. In this case, this
function returns ERR_SmallerDMAMemAllocated, and actual_size denotes

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