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均符's avatar
均符
Icon for New Contributor rankNew Contributor
5 years ago

Question for DDIO_IN IP

We wanna use DDIO_IN IP for capture data at twice the rate of the clock with a high-speed interface application in which the data is clocked at both edges of the clock.

The freq. of clock from our front-end is 148.5MHz for 1080p.

The FPGA chip we used is 5CGTFD7D5F27C7N.

There are errors when we capture data.

"The Cyclone device family supports both DDR SDRAM and FCRAM

memory interfaces up to 133 MHz." refering to http://www.altera.com/literature/hb/cyc/cyc_c51010.pdf(Implementing Double Data Rate I/O Signaling in Cyclone Devices).

How can we solve this problem?

1 Reply

  • NurAida_A_Intel's avatar
    NurAida_A_Intel
    Icon for Frequent Contributor rankFrequent Contributor
    5 years ago

    Hi Sir,

    Welcome to Intel Community.

    Yes, you are right. Cyclone devices support DDR SDRAM and FCRAM interfaces at up to 133 MHz through dedicated circuitry. There are few guidelines for user to meet 133 MHz performance for DDR SDRAM and FCRAM interfaces as below:

    • The DQS signal must be in the middle of the DQ group it clocks
    • Resynchronize the incoming data to the logic array clock using successive LE registers or FIFO buffers
    • LE registers must be placed in the LAB adjacent to the DQ I/O pin column it is fed by.

    For more details, you may refer to this Cyclone FPGA Family Data Sheet under section "External RAM Interfacing"--> https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/ds/ds_cyc.pdf

    Hope this helps.

    Thanks

    Regards,

    Aida