DDR4 uses POD (Pseudo Open Drain) instead of CTT as its IO buffer scheme and there's only a pull-up resistor for an individual IO in POD.
- Is the resistor here also used for DDR4 ODT?
- From DDR3 ZQ Calibration, ZQ calibration actually includes pull-up calibration and pull-down calibration for DDR3. Is there only a need for pull-up calibration and no need for pull-down calibration in DDR4 POD IO buffer?
