The card is used for sampling of input analog signals
through two channels and for further transmission of them to the applied program
for further processing. This card can also be used for synthesis of freeform
analog signals. There is a functions library "XdspAPI.dll"
for using this card in applied programs. This library realizes high level API
functions for controlling the modes of card work, for getting digitalized data
of the ADC memory and for data transmission for further signal synthesis to the
DAC memory.
The card supports PCI interface work in the modes
"Target" and "Master".
In the "Target" mode the driver of
the device exchanges data with the card serially to the order of the PC, in
"Master" mode to the order of data transmission
the card executes copying of internal memory to physical memory of the PC
without involving the central processor. That is so called DMA (Direct Memory Access)
mode. Card work in the "Master"
master mode provides transmission of internal memory to the PC memory on the
speed of 100 MB/Sec.
When the card works in "Master"
mode the following mechanism of digitalized signal transmission from the ADC
memory to the PC memory is used:
when initializing the card there appears a buffer (1024
KB DMA buffer) in the operative memory of the PC. This is the
full volume of internal ADC memory
when the sampling process is finished, after the DMA
transaction start order the card executes copying of a part of ADC
internal memory ( the range of the copied part is given by the functions XdspSetDMATransactionOffset è XdspSetDMATransactionLength)
to the DMA buffer of the PC without involving the central
processor of the PC.
the user supplement has direct access to the buffer
through the pointer to DMA buffer. To access the ADC memory "Master"
mode of card work is used. For DAC memory- "Target"
mode. The card supports apparatus interruption generation and
controlling the modes of its work. So interruption can be generated after
finishing the sampling process, after finishing DMA transaction or after
finishing both processes if such a mode is on. If you work with the card without
using apparatus interruption you can get the information about the end of
digitalizing process and DMA transaction through the status register.
DLL "XdspAPI.dll" library is connected to the program project
by standard methods for the used area of programming.
"XdspAPI_DLL.pas" module which describes imported
functions and extra constant values and types for Delphi programming area is
provided in a set with card software. The library supports the following function groups:
card opening (initialization)
and cardclosing (de-
initialization)
