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Altera_Forum's avatar
Altera_Forum
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18 years ago

What will happen without RREFB reference resistor in the GXB?

Hi everyone! I use the Stratix II GX device to design High-Speed system,but I forgot to use the RREFB reference resistor ports .Who can tell me what will happen without the RREFB reference resisto...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
18 years ago

Hello,

to tell you the truth, I would be surprized if normal GXB transceiver operation is possible anyway. RRef is used in GXB calibration block for termination resistor calibration. As an optimistic assumption, the calibration could fall back to meaningful default settings, possibly allowing GXB transceiver operation. Viewn pessimisticly, GXB could be completely halted due to bad calibration status. If your Stratix II devices are not yet assembled to PCB, I would consider to glue thin wires to RREF pads and connect them.

Regards,

Frank