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Altera_Forum
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8 years ago

EPCS4SI8N > EPCQ4ASI8N For Old Cyclone FPGA

I'm new here. Looking to migrate from Obsolete EPCS4SI8N to EPCQ4ASI8N and noticed The Fast Read Dummy Cycles is 8 on the new part while it is only 1 on the obsolete part. If I'm running the New Part at slow speeds, do I still need 8 Dummy Cycles or could I get away with 1 Dummy cycle, (due to the much slower clock speed)? Is it really time I'm waiting fore or is they an internal counter that must step thru 8 dummy cycles? All help greatly appreciated.

Mark

5 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    8 years ago

    Thank you. The link to the Altera AN727 does not work, (page not found).

    Also, Please keep in mind that I and switching to the EPCQ4ASI8N device, (4AS device).

    When you say I can configure the number of dummy cycles, how and where do I configure the number of dummy cycles?

    Thanks in Advance.

    Mark
  • Altera_Forum's avatar
    Altera_Forum
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    8 years ago

    Hi Mark,

    Please check the table:29 in below link.

    http://www.mouser.com/ds/2/612/cfg_cf52012-1098931.pdf.

    Note:Number of dummy cycles. When this number is from 0001 to 1110, the dummy cycles is from 1 to 14.

    Check the manual for more information

    Best Regards,

    Anand Raj Shankar

    (This message was posted on behalf of Intel Corporation)
  • Altera_Forum's avatar
    Altera_Forum
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    8 years ago

    Hi Mark and Anand,

    I have just found out the following part associated with the actual problem in the mentioned AN822 spec:

    The dummy clock requirement of the fast read (0Bh) and extended quad input fast read (EBh) commands:

    EPCQ—the dummy clock is configurable with the non-volatile configuration register (NVCR). When the EPCQ is used with a Cyclone® V, Arria® V or Stratix® V device, the dummy clock is configured to be 4, 10 or 12, depending on the byte-addressing mode and ASx1 or ASx4 configuration. However, in EPCQA devices, the dummy clock is fixed at 8 and 6 for fast read and extended quad input fast read respectively. Therefore you must regenerate the programming files, such as .pof, .jic, and .rpd.

    For further information: AN822 spec, 1.1 Migration Considerations, Operation Commands.

    Regards,

    Martin