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Altera_Forum's avatar
Altera_Forum
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14 years ago

CMU as transceiver reconfiguration simulation

Hi,

I'm currently working on dynamic transceivers reconfiguration (ALTGX and ALTGX_RECONFIG IPs) on Stratix IV GX device and I'm facing a problem I can't understand.

I succesfully simulated the dynamic reconfiguration (frequency switching by selecting the refclk input) of a 1-lane transmitter used in basic mode.

Now, I need to simulate the same reconfiguration feature, but on a CMU channel used as PMA-direct, receiver-only channel.

I generated all associated .mif files and I generated exactly the same signals than for the transmitter simulation. But when it comes to the simulation, the ALTGX_RECONFIG asserts the "error" output when trying to write the first word of the mif file... :(

I tried all the reconfiguration modes, I regenerated all my mifs, checked for the logical channel address, everything is OK, so I really don't know what to do. :confused:

Would it be possible that it comes from a problem with the simulation models, or am I doing something wrong ?

If someone has an example of ref clock switching for CMU receiver (PMA direct), that would be really helpful ! :)

Thank you very much for your time and help, and have a nice day !

Regards

2 Replies

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

    Hi everyone,

    I performed more advanced tests and I figured out that it is not only PMA direct receiver reconfiguration which fails, but any Receiver reconfiguration (PMA direct or Basic).

    The error is a "mif type" error, and the bit on the mif file, which leads the simulation to an error is reconfig_data(11) on the first line of the mif file. This bit is high for Tx and low for Rx. However, I have no idea what this difference means, and I couldn't fine any documentation about it.

    I simply want to dynamically switch from a reference clock to another at the multiplexer input of the receiver.

    I really can't see why receiver reconfiguration wouldn't be possible, because the option is available in the mega wizard...

    Thank you very much !

    Regards
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Hi everyone,

    Just in case someone would face the same problem, it is actually a misunderstanding in Altera's documentation.

    Actually, I tried "CMU PLL reconfiguration" mode and "Channel and CMU PLL reconfiguration" mode only, because the other one mentions the "Transmitter PLL", so I thought it was not appropriate.

    But actually, this is the only working mode for recevier only reconfiguration !!! The documentation is not very clear on this point unfortunately...

    So for people who face problems with Receiver only transceiver reconfiguration, think about selecting the channel_reconfig_mode : "110".

    Have a nice day.