AR# 46024

7 Series GTX - How do you override the Phase Interpolator (PI) phase?

Description

How can I override the CDR Phase Interpolator (PI) phase?

Solution

In order to set the CDR PI phase, please set the ports as follows:

RXCDRHOLD = 1'b0

RXCDROVRDEN = 1'b1

The PI phase is driven by 7 bits of RXCDR_CFG parameter.
The PI can vary the output phase with 128 steps spanning the VCO period (two UI due to DDR).

For IES silicon:

RXCDR_CFG[36:30]

For GES silicon:

RXCDR_CFG[15:9] The DRP address hex is 0A8[15:9]

In changing the phase, never jump more than 8 positions per update.

AR# 46024
Date 02/28/2013
Status Active
Type General Article
Devices