Patent ID: 7640463
Filing Date: 2009-12-29
Classification: G01R

Abstract:
1. An eye finder diagnostic circuit for a serial link receiver comprising: an existing capture latch for the serial link receiver having an input tied to a receive equalizer output, the existing capture latch residing on an integrated circuit; and, a single extra capture latch having a first input tied to the same input as the existing capture latch; wherein the single extra capture latch resides on the same integrated circuit as the existing capture latch; said single extra capture latch having two further inputs and an output, one of said two inputs being a clock input and the other one of said two inputs being a variable voltage threshold input, said clock input connected to the output of the single phase interpolator and said variable voltage threshold input connected to the output of the single voltage generator; and a digital post processing (DPP) circuit including a microprocessor connected to the output of the existing capture latch and the single extra capture latch, for processing the output of the existing capture latch and the single extra capture latch, where the digital post processing (DPP) circuit is configured to determine a receive eye opening by controlling the clock location, controlling a reference voltage generated by the single voltage generator, and comparing the output of the single extra capture latch with the output of the existing capture latch; wherein the eye finder diagnostic circuit for the serial link receiver resides on a chip housing the receive equalizer.