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Altera_Forum
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12 years ago

DQS frequency of a Cyclone IV EP4CE40F29C8 with 2x DDR2

Hello,

A EP4CE40F29C8 (core voltage 1.2V) uses two Micron MT47H32M16 in parallel in x8 mode on bottom banks 3 & 4 creating a 32bit bus DDR2. Using ALTMEMPHY HPCII at half rate. Pin assignments are correct and it compiles fine with no errors. There are however four critical warnings concerning the four DQS pins:

Critical Warning (165040): The DQS pin "DDR_DQS[3]" has a frequency of 160.0 MHz which is not supported at location PIN AF26

Info (165017): Location PIN AF26 can support a maximum DQS frequency of 134.01 MHz

The same warning is given for all four DQS pins placed in: AF26, AE18, AE10, AD7

The maximum frequency quartus suggests, is the frequency when using row banks. Changing the speed grade to C7 gives the same warning with a suggested frequency of 150MHz, which is again the frequency when using row banks. According to the datasheet and the External Memory Interface Spec Estimator tool by altera, the C8 grade supports DDR2 up to 167MHz on column banks.

It is not possible to run DDR2 (MT47H32M16) at 133MHz because the minimum tRTP time of 7.5ns cannot be achieved.

What is going wrong here?

Thnx in advance!

1 Reply

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

    I have the same problem with EP4CE115F29C7N and MT47H64M16HR-25EIT x2……

    “

    Critical Warning (165010): altmemphy pin placement has critical warnings

    Critical Warning (165040): The DQS pin "ddr2b_dqs[0]" has a frequency of 166.69 MHz which is not supported at location PIN AD7

    Info (165017): Location PIN AD7 can support a maximum DQS frequency of 150.02 MHz

    Critical Warning (165040): The DQS pin "ddr2b_dqs[1]" has a frequency of 166.69 MHz which is not supported at location PIN AF11

    Info (165017): Location PIN AF11 can support a maximum DQS frequency of 150.02 MHz

    Critical Warning (165040): The DQS pin "ddr2b_dqs[2]" has a frequency of 166.69 MHz which is not supported at location PIN AF26

    Info (165017): Location PIN AF26 can support a maximum DQS frequency of 150.02 MHz

    Critical Warning (165040): The DQS pin "ddr2b_dqs[3]" has a frequency of 166.69 MHz which is not supported at location PIN AE18

    Info (165017): Location PIN AE18 can support a maximum DQS frequency of 150.02 MHz

    ”

    The massage in the ALTMEMPHY says :" Cyclone IV E speed grade 7 does not support DDR2 SDRAM operation above 150.0MHz on the left or right I/O banks. This design must br placed on the top or bottom I/O banks"

    I followed this ,but it didn't work at all. All the pins the Quartus warning shows are on the bottom !

    I tried 4 groups, and the man on the# 1 stair tried different 4 groups.

    All the 6 DQ groups on the bottom side we had tried but no one could run on a freq over 150MHz?

    What's wrong??