ADLINK Technology PCI-7200 Spécifications télécharger pdf (Page 81)

Double Buffer Mode Principle •• 71

Double Buffer Mode Principle

The data buffer for double-buffered DMA DI operation is a

circular buffer logically. It logically divided into two equal halves.

The double-buffered DI begins when device starts writing data

into the first half of the circular buffer (Figure 6-1a). After device

begins writing to the second half of the circular buffer, you can

copy the data from the first half into the transfer buffer (Figure 6-

1b). You now can process the data in the transfer buffer

according to application needs. After the board has filled the

second half of the circular buffer, the board returns to the first

half buffer and overwrites the old data. You now can copy the

second half of the circular buffer to the transfer buffer (Figure 6-

1c). The data in the transfer buffer is again available for process.

The process can be repeated endlessly to provide a continuous

stream of data to your application (Figure 6-1d).

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ADLINK Technology PCI-7200 Spécifications Page 81