Arria® V Device Handbook: Volume 2: Transceivers

ID 683573
Date 5/29/2020
Public
Document Table of Contents

1.1.4.5. Calibration Block

The calibration block calibrates the differential OCT resistance and analog circuitry in the transceiver PMA to ensure the functionality is independent of PVT. It is also used for duty cycle calibration of the clock line at serial data rates above 4.9152 Gbps.

Up to two calibration blocks are available for the Arria V transceiver PMA.

Figure 22. Calibration Block Location and Connections in Arria V Devices with Transceivers on the Left Side of the Device Only


Figure 23. Calibration Block Location and Connections in Arria V Devices with Transceivers on Both Sides of the Device


The calibration block generates a constant internal reference voltage that is independent of PVT variations using the external reference resistor. The resulting reference currents are used to calibrate the transceiver banks.

Note: You must connect a separate 2 kΩ (tolerance maximum of ±1%) external resistor on each RREF pin to ground, except for Arria GZ devices. In Arria V GZ devices, you must use a 1.8 kΩ (maximum tolerance +/- 1%) external resistor. To ensure the calibration block operates properly, the RREF resistor connection in the board must be free from external noise.