The TLK10022 is a dual-channel multi-rate link aggregator intended for use in
high-speed bi-directional point-to-point data transmission systems. The device allows for a
reduction in the number of physical links required for a certain data throughput by multiplexing
multiple lower-rate serial links into higher-rate serial links.
Each channel of the TLK10022 has a low-speed interface which can accommodate one, two,
three, or four bidirectional serial links running at rates from 250 Mbps to 5 Gbps (maximum of 10
Gbps total throughput). The device’s high speed interfaces (one per channel, bidirectional) can
operate at rates from 1 Gbps to 10 Gbps. When a channel is configured for a certain multiplexing
ratio (1-to-1, 2-to-1, 3-to-1, or 4-to-1), the high speed side will operate at a fixed multiple of
the low speed rate (e.g., four times faster for 4-to-1 mode) regardless of the number of lanes
connected. Filler data will be placed on any unused lanes in order to keep the interleaved lane
ordering constant. This allows for low speed lanes to be hot swapped during normal operation
without requiring a change in configuration.
The device has multiple interleaving/de-interleaving schemes that may be used depending
on the data type. These schemes allow for the low speed lane ordering to be recovered after the
lanes are transmitted over a single high-speed link. There is also a programmable
scrambling/de-scrambling function available to help ensure that the high-speed data has suitable
properties for transmission (i.e., sufficient transition density for clock recovery and DC balance
over time) even for non-ideal input data.
A 1:1 mode is also supported for data rates ranging from 0.5 Gbps to 2.5 Gbps, whereby
both low speed and high speed are rate matched. The TX and RX datapaths are also independent, so
the TX and RX can operates in different modes (this excludes 3:1 mode which requires both the TX
and RX path to run in the same mode). This independence is restricted to using the same low speed
line rate. For example, the TX can operate at 4 × 2.5 Gbps while RX operates at 1 x 2.5 Gbps.
The individual Low Speed lanes may also operate at independent rates in byte
interleave mode, provided they are operating at integer multiples. The High Speed line rate must be
configured based on the fastest Low Speed line rate.
The TLK10022 has the ability to perform lane alignment on 2, 3, or 4 lanes with up to
four bytes of lane de-skew.
Both the low speed and high speed side interfaces (transmitters and receivers) use CML
signaling with integrated termination resistors and feature programmable transmitter de-emphasis
levels and adaptive receive equalization to help compensate for media impairments at higher
frequencies. The device’s serial transceivers used are capable of interfacing to optical modules as
well as higher-loss connections such as PCB backplanes and controlled-impedance copper cabling.
To aid in system synchronization, the TLK10022 is capable of extracting clocking
information from the serial input data streams and outputting a recovered clock signal. This
recovered clock can be input to a jitter cleaner in order to provide a synchronized system clock.
The device also has two reference clock input ports and a flexible internal PLL, allowing for
various serial rates to be supported with a single reference clock input frequency.
The device has various built-in self-test features to aid with system validation and
debugging. Among these are pattern generation and verification on all serial lanes as well as
internal data loopback paths.