Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

Sides for DDR2 DQ and DQS

Hi, All

Our design is going to use 2 Sides of EP3C40, Because there are not enough DQ pins in 1 Side. For better performance, which two should chose?

TOP and Bottom or Bottom and Right, or Others, and Why?

Thanks

5 Replies

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

    --- Quote Start ---

    sorry i was too quick... i was talking about stratix3 not cyclone...

    --- Quote End ---

    Is it the same in Cyclone III, I am not fimilar with stratix3

    And I choosed TOP and Bottom, Will these two sides too far away, which will cause bad STA result?
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    16 years ago

    sorry i was too quick... i was talking about stratix3 not cyclone...

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

    Forgot the why: io's and pll's have more dedicated hardware for ddr on top and bottom

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

    top bottom are typacally used for memomry applications, left right for serdes applications.