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Altera_Forum's avatar
Altera_Forum
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17 years ago

Full Rate Mode in DDR2 HP Controller

Hello, I'm new to the High-Performance DDR2 Controller and have a question about the documentation that I hope some can clear up. I want to run my controller in Full Rate Native Interface Mode but I don't see any timing diagrams for that mode. Can anyone explain this, or maybe there is not such a mode?

thanks,

joe

6 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    All timing diagrams in HP controller manual are for native mode, full rate, as said at page 4-11.

  • Altera_Forum's avatar
    Altera_Forum
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    Hello, thanks for responding to my post. I looked at page 4-11 and I only see timing diagrams for

    Full Rate Write Avalon Interface,

    Half Rate Write, Native

    Full Rate Read Avalon Interface

    Half Rate Read Avalon Interface.

    But I don't see a Full Rate Native Interface Mode, which timing diagram should I follow?

    Sorry for being so stupid here and I appreciate your patients.

    Thanks,

    joe
  • Altera_Forum's avatar
    Altera_Forum
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    I refer to ddr & ddr2 sdram high-performance controller v7.2 user guide

    --- Quote Start ---

    These interface requests are for the native interface.

    ...

    All figures show full rate controllers.

    --- Quote End ---

  • Altera_Forum's avatar
    Altera_Forum
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    Hello, now I see the disconnect. I'm using DDR & DDR2 SDRAM High-Performance Controller v8.0 User Guide documentation which is different than 7.2. Do you think there is a difference between 7.2 and 8.0? Looking at the timing diagrams briefly there appears some difference. Could you you at the 8.0 doc and comment on what they have when you have some free time.

    Thanks for your help,

    joe
  • Altera_Forum's avatar
    Altera_Forum
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    Looking closer at 7.2 I see that the local_addr is broken down into other signals this is not done in 8.0, do you know where I can find where it breaks that down. I've looked through the verilog code but I can't find that information.

    thanks,

    joe
  • Altera_Forum's avatar
    Altera_Forum
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    I downloaded Quartus V8.0, but didn't yet install it. I don't expect, that the basic decoding scheme of local addresses has been changed with V8.0 HP controller, cause the mapping is almost obvious and doesn't give much room for alternatives to my opinion. But I may be wrong. I also wasn't aware of big differences in local bus interface timing between half and full rate, except for the latency when measured in clock cycles.

    However, I'll take a look at the V8.0 HP controller.