Intel® Arria® 10 Core Fabric and General Purpose I/Os Handbook

ID 683461
Date 10/25/2023
Document Table of Contents Guideline: VREF Sources and VREF Pins

For Intel® Arria® 10 devices, consider the following VREF pins guidelines:

  • Intel® Arria® 10 devices support internal and external VREF sources.
    • There is an external VREF pin for every I/O bank, providing one external VREF source for all I/Os in the same bank.
    • Each I/O lane in the bank also has its own internal VREF generator. You can configure each I/O lane independently to use its internal VREF or the I/O bank's external VREF source. All I/O pins in the same I/O lane use the same VREF source.
  • The internal VREF is supported only for external memory interfaces.
  • You can use the internal VREF with calibration to support DDR4 using the POD12 I/O standard. The internal VREF is supported only for the POD12 I/O standard.
  • You can place any combination of input, output, or bidirectional pins near VREF pins. There is no VREF pin placement restriction.
  • The VREF pins are dedicated for voltage-referenced single-ended I/O standards. You cannot use the VREF pins as user I/Os.

For more information about pin capacitance of the VREF pins, refer to the device datasheet.