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C/C++ Libraries
5.13 _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)
int W_7200_Alloc_DMA_Mem (U32 *buff, U32 *handle, U32
buf_size, U32 *actual_size)
Visual Basic (Windows 95)
W_7200_Alloc_DMA_Mem (buff As Long, handle As Long, ByVal
buf_size As Long, actual_size As Long ) As Long
@ Argument
buff : 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.
handle: The handle of system DMA memory returned from system.
Use this handle in _7200_DI_DMA_Start or _7200_DO_DMA_Start.
buf_size: Bytes to allocate. Please be careful, the unit of this parameter
is BYTE, not SAMPLE.
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