5.14 _7200_Alloc_DMA_Mem. ADLINK Technology PCI-7200

5.14 _7200_Alloc_DMA_Mem

@ Description

Contact Windows 95/98 system to allocate a block of contiguous memory for single-buffered DMA transfer. This function is only available in Windows 95/98 version.

@ Syntax

Visual C++ (Windows 95/98) int W_7200_Alloc_DMA_Mem (U32 *buff, U32 *handle, U32 buf_size, U32 *actual_size)

Visual Basic (Windows 95/98)

W_7200_Alloc_DMA_Mem (buff As Long, handle As Long, ByVal buf_size As Long, actual_size As Long ) As Long

@ Argument buff : handle: buf_size:

The start address of the user buffer for DMA data transfer. This buffer will be attached to the DMA memory allocated by this function. When using this

DMA memory handle as an argument of

W_7200_DI_DMA_Start function, DI data will be copied to this buffer. When using this DMA memory handle as an argument of W_7200_DO_DMA_Start function, the data stored in this buffer will be the DO data.

The handle of system DMA memory returned from system. Use this handle in _7200_DI_DMA_Start or

_7200_DO_DMA_Start.

Bytes to allocate. Please be careful, the unit of this parameter is BYTE, not SAMPLE.

C/C++ & DLL Libraries

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actual_size: The actual size system allocate for DMA memory.

The unit is BYTE. 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 the actual size of allocated memory.

@ Return Code

ERR_NoError

ERR_SmallerDMAMemAllocated

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C/C++ & DLL Libraries