This library is extracted from code in Quartus releases using gen_platform_ip.sh
in this directory.  Point the script at a Quartus release and it will do the rest.
The module names are modified to make them unique, replacing the leading "altera"
with "platform_utils".

The SDC files are here instead of in a par directory to keep all the Qsys
code together.

Extracted components include:
  * Qsys Avalon-MM Clock Crossing Bridge
  * Qsys Avalon-MM Pipeline Bridge


Notes

(1) Copyrights should be changed to BSD/MIT licenses.

(2) platform_utils_avalon_mm_clock_crossing_bridge.v must be modified by hand
    (as of 18.0) to export the s0_space_avail_data port so that the clock crossing
    FIFO can be used. This allows us to transform the waitrequest protocol into
    an almost full protocol. Using almost full, pipelines can be added without
    flow control at each stage.

    Suggested method: first check in the base copy of
    platform_utils_avalon_mm_clock_crossing_bridge.v and then edit it and check
    in the changed version. This way we have a history of changes.
