ADLINK PCI-7200 - Manual (Page 74)

62 C/C++ Libraries
Visual Basic (Windows 95)
W_7200_DI_DMA_Start (ByVal mode As Byte, ByVal
count As Long, ByVal handle As Long, ByVal
wait_trg as Byte, ByVal trg_pol As Byte,
ByVal clear_fifo As Byte, ByVal disable_di
As Byte) As Long
C/C++ (DOS)
int _7200_DI_DMA_Start (U8 mode, U32 count, U32
*di_buffer, Boolean wait_trig, U8 trig_pol,
Boolean clear_fifo, Boolean disable_di)
@ Argument
mode:Digital Input trigger modes
DI_MODE0: Internal timer pacer (TIME 0)
DI_MODE1: External signal I_REQ rising edge
DI_MODE2: External signal I_REQ falling edge
DI_MODE3: I_REQ & I_ACK handshaking
count: For non-double-buffered DI, this parameter denotes the
number of digital input samples to read. For double-buffered DI, it
is the size of circular buffer (in samples, not in bytes).
handle (Win95): The handle of system DMA memory. In Win-
dows 95, before calling _7200_DI_DMA_Start, depending on
using double-buffer mode or not, either _7200_Alloc_DMA_Mem
or _7200_Alloc_DBDMA_Mem must be called to allocate a contig-
uous DMA memory and get the handle.
di_buffer (DOS): If double buffer mode is disabled, this is the
start address of the memory buffer to store the DI data. If double
buffer mode is enabled, this memory buffer is actually of no use.
But the buffer size still must be larger than the number of count
(count*4 bytes). Use this buffer as transfer buffer in
_7200_DblBufferTransfer to make use of this buffer.
**This memory should be double-word alignment.
wait_trig: The waiting status of trigger
DI_NONWAITING: the input sampling will start immediately