The block memories in the Virtex-II architecture are capable of supporting data bus widths of up to 36-bits. A self-addressing FIFO reference design uses these block memories to store both data and address information in a single memory location. This application note describes FIFO designs where no external counters are required. Only flag and status information logic is used. The resulting FIFOs are not fast (around 150 MHz). Their advantage is in using only one clock load. In addition, the status mechanism is very simple making FIFOs more suitable for data throttling in continous data systems instead of the full or empty detection required in fram based data systems.
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