User`s guide

C/C++ Libraries • 59
@ Syntax
Visual C/C++ (Windows 95)
int W_7300_DI_DMA_Start (int card_number, HANDLE memID, U32
count, int clear_fifo, int disable_di)
Visual Basic (Windows 95)
W_7300_DI_DMA_Start (ByVal card_number As Long, ByVal memID As
Long, ByVal count As Long, ByVal clear_fifo As
Long, ByVal disable_di As Long) As Long
C/C++ (DOS)
int _7300_DI_DMA_Start (int card_number, int mode, U32 *buffer,
U32 count, int clear_fifo, int disable_di)
@ Argument
card_number: The card number of the PCI-7300A card.
mode (DOS): CHAIN_DMA: chaining DMA mode. By using the
scatter-gather capability of PCI-7300A, the
input data is put to several buffers which chained
together.
NON_CHAIN_DMA: The input data is stored in a block
of contiguous memory.
memID (Win-95): the memory ID of the allocated system DMA memory.
In Windows 95 environment, before calling
W_7300_DI_DMA_Start, W_7300_Alloc_DMA_Mem must
be called to allocate a DMA memory.
W_7300_Alloc_DMA_Mem will return a memory ID for
identifying the allocated DMA memory, as well as
the linear address of the DMA memory for user to
access the data.
buffer (DOS): With non-chaining mode, this is the start address
of the memory buffer to store the DI data. With
chaining-mode (scatter-gather), this is the
address (pointer) of first DMA descriptor node.
**With non-chaining mode, this memory should be
double-word alignment. With chaining-mode, this
address should be 16-byte alignment. Also the
pointer of all DMA descriptor nodes should be
16-byte alignment.
count: With non-chaining mode, this is the number of
digital input to transfer. The unit is
double-word (4-byte). The value of
count
can not
exceed 2^21 (about 2 million). With chaining mode,
please set this argument to 0. The number of
digital input is determined by the information in
DMA descriptor nodes.
clear_fifo: 0: retain the FIFO data
1: clear FIFO data before perform digital input
disable_di: 0: digital input operation still active after DMA
transfer complete
1: disable digital input operation immediately
when DMA transfer complete