IDT 89HP0504UB Data Sheet

7

February 8, 2011

Eye Diagram Parameters

Receiver Impedance

The table below shows how the receiver impedance changes based on input and output pin states.

Feature

Feature Type

Parameter Names for

Programming via Pins

Input equalization

Main eye optimization

A0RXEQ, A1RXEQ, B0RXEQ, B1RXEQ

Range: 0dB to 14dB (plus additional auto-

boost up to 10dB for long connections)

Output differential signal

swing (peak-to-peak) and

output de-emphasis

Main eye optimization

A0TXSW, A1TXSW, B0TXSW, B1TXSW

Range: 0.5V to 0.95V for swing

Range: 0 to -6.5dB for de-emphasis

Table 1 Quick Reference: Parameters Used for Eye Optimization

Mode

Control Inputs

Rx

Terminations

Description

PDB

[A,B]RXDETEN

RSTB

Full IC

Power-down

0

X

X

Hi-Z

Receiver terminations placed in Hi-Z.

Channel Dis-

abled

1

1

0

Hi-Z

Receiver detect in reset.

Receiver terminations placed in Hi-Z.

Channel

Enabled

10

1

50

Ω

Receiver detect disabled.

Receiver terminations set to 50

Ω.

Channel Dis-

abled

1

1

1

Hi-Z

Receiver detect enabled.

No far-end receiver detected.

Receiver terminations placed in Hi-Z.

Channel

Enabled

11

1

50

Ω

Receiver detect enabled.

Valid receiver detected.

Receiver terminations set to 50

Ω.

Table 2 Receiver Impedance