I am getting an incorrect waveform / computer hang, when I run Waveform Generation in the interrupt mode with no onboard FIFO Hardware: Signal Sources (AWG/FG/AO), Multifunction DAQ (MIO)
Problem: Waveform Generation using Interrupts and no onboard FIFO does not output a nice, continuous sine wave. The waveform generation is also failing if I use my CD-ROM as a CD-Player at the same time as the Waveform output. This does not happen when I use the AT-MIO E-2, which has a FIFO capability. Why does this happen? Solution: If you use only one DMA channel, whenever the DMA controller encounters a page break (every 64Kbytes on ISA computer), it must be reprogrammed to operate on the next page. This could cause the waveform to terminate easily, or generate points erradically. When using the CD-ROM as a player in interrupt mode, interrupt latencies(the time between the interrupt occuring, and the interrupt being serviced) could be high causing the waveform to terminate. The AT-MIO-16E-2 has an onboard FIFO which can store up to the next 2048 samples to output. This bufffer allows for greater interrupt latencies, and DMA reprogramming since the board ahs samples left to do in the buffer whil the reprogramming or latency is occuring. Related Links: Attachments:
Report Date: 10/19/1995 Last Updated: 06/11/2004 Document ID: 0EIF7HMC |
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