7.3. Power-up Calibration
After the device is powered up and programmed, PreSICE automatically initiates the calibration process. The calibration process may continue during device programming. The time required after device power-up to complete the calibration process can vary by device. The total time taken can extend into the user-mode. The cal_busy signals deassert to indicate the completion of the calibration process. You must ensure that the transceiver reset sequence in your design waits for the calibration to complete before resetting the transceiver PLL and the transceiver channel.
The PreSICE may still control the internal configuration bus even after power-up calibration is complete. You can request access when needed. If a system has an fPLL, an ATX PLL, and channels, the fPLL cal_busy signal goes low first. The ATX PLL cal_busy signal goes low after the channels’ tx_cal_busy and rx_cal_busy signals. Intel recommends that you wait until all *_cal_busy signals are low before requesting any access.
All power-up calibration starts from Vreg calibration for all banks and channels.
PCIe* link does not allow user recalibration, so you must perform power-up calibration.
Furthermore, power-up calibration for channels configured with the PCIe* protocol require a reference clock. Without the presence of a reference clock, power-up calibration does not start but waits indefinitely, so supply a reference clock to the PCIe* refclk pin for the power-up calibration process.
- Vreg calibration for all banks and channels.
- Wait for PCIe* reference clock toggle.
- PCIe* Hard IP 0 calibration (if used).