Channel-Link (C-Link) by National Semiconductor is a high-speed interface for cost-effectively transferring data at rates from 250 megabits/second to 6.4 gigabits/second over backplanes or cables.
National Semiconductor introduced the first Channel-Link chipsets in the late 1990s to provide an alternative to continually widening data buses to get higher throughput.
In cable applications, it uses one twisted pair in order to transmit a clock signal, and on the remaining differential pairs it transmits digital data at a bit rate that is seven times the frequency of the clock signal.
The eight-lane chipset has 48 single ended inputs and outputs because it uses one of the 7 serialized bits/lane to DC-balance the other six bits.
It uses the 28-bit Channel-Link version and specifies for a clock rate up to 85 MHz for a total throughput of 2.38 Gbit/s.