Intel cPCI-7200 Benutzerhandbuch
40
• C/C++ Libraries
the actual size of allocated memory for each half of circular buffer.
@ Return Code
ERR_NoError
ERR_SmallerDMAMemAllocated
5.16 _7200_Free_DBDMA_Mem
@ Description
Release a system circular buffer DMA memory under Windows 95/98
environment. This function is only available in Windows 95/98 version. For
double-buffered transfer principle, please refer to Section 6 “Double
Buffered Mode Principle”.
environment. This function is only available in Windows 95/98 version. For
double-buffered transfer principle, please refer to Section 6 “Double
Buffered Mode Principle”.
@ Syntax
Visual C++ (Windows 95)
int W_7200_Free_DBDMA_Mem (U32 handle)
Visual Basic (Windows 95)
W_7200_Free_DBDMA_Mem (ByVal handle As Long ) As Long
@ Argument
handle:
The handle of sys tem DMA memory to release.
@ Return Code
ERR_NoError
5.17 _7200_DI_DMA_Start
@ Description
The function will perform digital input N times with DMA data transfer by using
one of the following four sampling modes :
one of the following four sampling modes :
1. pacer trigger (internal timer trigger)
2. external rising edge I_IRQ
3. external falling edge I_IRQ
4. I_REQ & I_ACK handshaking
It will take place in the background which will not stop until the Nth input data is
transferred or your program execute _7200_DI_DMA_Stop function to stop the
process.
transferred or your program execute _7200_DI_DMA_Stop function to stop the
process.
After executing this function, it is necessary to check the status of the operation
by using the function _7200_DI_DMA_Status. The PCI-7200 Bus mastering
DMA is different from traditional PC style DMA. Its description is as follow :
by using the function _7200_DI_DMA_Status. The PCI-7200 Bus mastering
DMA is different from traditional PC style DMA. Its description is as follow :