rtd cpuModule CMA22M Series, Руководство пользователя

Страница: 12 / 106

4 CMA22M cpuModule BDM-610000069 Rev A
The aAIO also provides interrupts on threshold crossing. A high and low threshold can be set for each channel.
After sampling is started, an interrupt can be generated if any of the signals cross the threshold. This removes
some of the CPU load for simple monitoring tasks.
A DMA engine with a scatter-gather table allows efficient, robust handling of data. Up to 64 DMA buffers can be
assigned to each channel. After filling each buffer, an interrupt can be generated to inform the driver that buffer
is full so that the driver can empty it or assign a new buffer. Because many buffers can be assigned, interrupt
latency problems are mitigated. Also, since each channel has it’s own buffer, software does not have to
de-interlace the data. The DMA engine can send the data to anywhere in 4GB memory space.