ADLINK PCI-7200 - Manual (Page 67)

C/C++ Libraries 55
5.13 _7200_Alloc_DMA_Mem
@ Description
Contact the Windows 95/98 system to allocate a block of contigu-
ous memory for single-buffered DMA transfer. This function is only
available in Windows 95/98.
@ 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
the W_7200_DI_DMA_Start function, DI data will be copied to this
buffer. When using this DMA memory handle as an argument of
the 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 sys-
tem. 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.