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ADLINK cPCI-7300 User Manual

Page 64

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C/C++ Libraries

@ Return Code

NoError
AllocDMAMemFailed

5.13 _7300_Free_DMA_Mem

@ Description

Deallocate a system DMA memory under Windows 95 environment. This
function is only available in Windows 95 version.

@ Syntax

Visual C/C++ (Windows 95)

int W_7300_Free_DMA_Mem (HANDLE memID)

Visual Basic (Windows 95)

W_7300_Free_DMA_Mem (ByVal memID As Long ) As Long

@ Argument

memID:

The memory ID of the system DMA memory to
deallocate.

@ Return Code

NoError

5.14 _7300_DI_DMA_Start

@ Description

The function will perform digital input by DMA data transfer.
It will take place in the background which will not stop until the N-th input data
is transferred or your program execute the _7300_DI_DMA_Abort function to
stop the process.

After executing this function, it is necessary to check the status of the operation
by using the function _7300_DI_DMA_Status. The PCI-7300A Bus
mastering DMA is different from traditional PC style DMA. Its description is as
follows:

Bus Mastering DMA mode of PCI-7300A:
PCI bus mastering offers the highest possible speed available on the
PCI-7300A. When the function _7300_DI_DMA_Start is executed, it will
enable PCI bus master operation. This is conceptually similar to DMA (Direct
Memory Access) transfers in a PC but is really PCI bus mastering. It does not