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SK_VA's avatar
SK_VA
Icon for Occasional Contributor rankOccasional Contributor
5 years ago

Series Termination with Calibration in Cyclone V

Hi,

I need to use Series termination with calibration for 33 signals on a Cyclone V FPGA(5CEBA9F23C7).

PIN_AB11 is used as the RZQ pad.

I am using ALTOCT IP with Calibrate OCT on power up. This gives seriesterminationcontrol of 16bits and I connected 16 of the 33 signals to this port and also assigned corresponding TERMINATION_CONTROL_BLOCK in the qsf.

But when I create a second instance of ALTOCT IP and connect the same rzq pin as the reference resistor input. It shows the following error.

Error (15700): Termination calibration block atom "rzq_calib:rzq_1|rzq_calib_alt_oct_power_k4e:rzq_calib_alt_oct_power_k4e_component|sd1a_0" uses RZQIN port, which must be connected to a dedicated I/O atom with no other fanout

Is there a limitation on the number of signals that can be calibrated with a rzq reference resistor.

1 Reply

  • AminT_Intel's avatar
    AminT_Intel
    Icon for Regular Contributor rankRegular Contributor
    5 years ago

    Hello,

    The problem is that both is assigned to the same rzq. One calibration sets need a rzq by itself. It is only generating 1 calibrated termination control sets. When you fanout the termination control sets, the Quartus disallow it, because it doesn't have separate results. If all the pins should be using the same calibrated termination control set, then assign them to the same rzq. If 2 sets of pins using different calibrated termination control set, then you need separate rzq and calibration IP.

    Hope this helps.

    Thanks.