Filter
Top Products
C/C++ Libraries
•
45
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.
@ 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 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