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Altera_Forum's avatar
Altera_Forum
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12 years ago

.sdc timing for opencores MAC v9.1

Hello

I‘ m integrating the opencores MAC 9.1 in our Cyclone IV device. For an application I use a simple socket server from the NIOS template. After some Ping commands (~100) I get errors on “Frame dropped”. I’m not an expert in time quest, but I would like to set the a correct timing (.sdc file).

System:

Cyclone IV EP4CE40F23C8

opencores MAC v9.1

MII interface to a DS83848C PHY

NIOS II type fast on 50MHz

Please, can you some one an appropriated .sdc file for the opencores mac v9.1?

1 Reply

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    12 years ago

    I'm not familiar with the opencores Mac, but are you getting this error message from the software? In that case your problem doesn't come from the .sdc file.

    The timing constraints that you set in the .sdc files set the timing requirements on the hardware level. Timing errors on that level are detected during compilation of the Quartus project, in the TimeQuest tool. If you are getting this error message from the embedded software, it probably means that you have a runtime timing problem, i.e. that your software is too slow to cope with the incoming traffic, and the driver drops some frames. In that case you should rather have a look on how you can optimize your design, either on the hardware level (increasing the system frequency, using a memory cache, or on-chip memory buffers or tightly coupled RAMs) or on the software level (compiler optimizations, code optimization).