GS3281 datasheet(20/97 Pages) SEMTECH

20 / 97 page

GS3281

Final Data Sheet

Rev.7

PDS-061453

January 2019

20 of 97

Semtech

Proprietary & Confidential

www.semtech.com

If the CDR cannot lock to any of the valid rates in automatic mode or the selected rate in

manual mode, the signal can automatically be bypassed to the output. If the CDR does

lock to the incoming signal, the re-timed and bypassed (if manual bypass control

enabled) signals are available at the appropriate output. See the Section 4.7 for more

details.

4.3.3 Lock Time

4.3.3.1 Synchronous and Asynchronous Lock Time

Synchronous lock time is defined as the time it takes the device to re-lock to an existing

signal that has been momentarily interrupted or to a new signal of the same data rate

as the previous signal which has been quickly switched in.

Asynchronous lock time is defined as the time it takes the device to lock when a signal

is first applied to the serial digital inputs, or when the signal rate changes. The

asynchronous and synchronous lock times are defined in Table 2-3.

Note: To ensure synchronous lock times are met, the maximum interruption time of the

signal is 10μs for an SD-SDI signal. HD, and 3G signals must have a maximum

interruption time of 6μs. The new signal, after interruption, must have the same

frequency as the original signal but may have an arbitrary phase.

Table 4-2: Detected Data Rates

STAT_DETECTED_

RATE [2:0]

Detected Data Rate

Unlocked

MADI (125Mb/s)

SD (270Mb/s)

HD (1.485Gb/s)

43G (2.97Gb/s)

Reserved

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