wiki:WARPLab/BufferSizes

Version 6 (modified by chunter, 9 years ago) (diff)

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Large Buffer Support

In WARPLab 7.4 and earlier, all transmit and receive samples were stored in buffers of BRAM directly on the FPGA. As of WARPLab 7.5, these samples are buffered in the DRAM SODIMM attached to the WARP v3 hardware.

WARPLab 7.4 WARPLab 7.5 (4RF) WARPLab 7.5 (2RF)
Tx Maximum # of Samples 32 kS 56 MS 112 MS
Tx Maximum Duration at 40MHz Bandwidth 819.2 µs 1.468 s 2.9360 s
Rx Maximum # of Samples 32 kS 64 MS 128 MS
Rx Maximum Duration at 40MHz Bandwidth 819.2 µs 1.6777 s 3.3554 s

The table above summarizes the maximum buffer sizes for the WARPLab 7.5 design. Since the buffer space is divided among RF interfaces, the 2RF design can store more samples than the 4RF design. WARPLab 7.5 maintains full backward compatibility with WARPLab 7.4, so all existing scripts compatible with WAPRLab 7.4 will "just work" with the new design and will use the existing WARPLab 7.4 limitations on buffer sizes.

Performance Considerations

With all of the extra buffer space that the hardware design is capable of, the chief limitation on usable buffer sizes shifts burden to the user's PC. Each sample in a MATLAB workspace is stored as a double precision real and a double precision imaginary value. The below table shows the size (in bytes) of N

32

Enabling Large Buffers