Hardware and Software Design • Manufacturing Services
page 5
The Data in the Output FIFO passes through the DMA Xilinx before the PLX [PCI interface] has access. The data is
written into the Output FIFO at 66 MHz and read out at 33 Mhz. The interface supports DMA and target reads.
The 2:1 load to read bandwidth insures rapid and efficient data transfer in Retrieve mode.
The FE design includes a software write path and load register to allow the software to load data words into the
Input FIFO directly. The FE design also has a 12 bit counter that can be used to load data automatically into the
FIFO for performance testing. The Counter inserts data at 33MHz. into the data path to provide a continuous data
stream. The counter can be used to cause Direct or Capture mode operations. Retrieve can be used after
capture to read the data back for test and development purposes.
The hardware as of this revision has all Channels and all data paths tested. An 8 channel LVDS data simulator was
used with multiple patterns, speeds, and programming scenarios to check on all modes of operation.