Occasional ContributorInterface LVDS to Gigabit transceivers
Hi,
I need to interface LVDS transmitter channels from a Cyclone 10 GX to Gigabit receivers in Arria 10, in other words from LVDS to 1.5V PCML. The reason is backwards compatibility in our hardware. Is it possible with only AC-coupling or am I missing something?
The link will be asynchronous, clock recovery at the receiver, double data rate, clock frequency of 1GHz.
Hi,
From my understanding, you are inquiring about interfacing the C10GX LVDS TX with the A10 XCVR RX. In principle, this should be feasible, provided that the LVDS TX output specifications are compatible with the XCVR RX input requirements.
Below are several key aspects (not exhaustive) that you should review and verify:
1. Data Rate
Ensure that the selected data rate is supported by both the LVDS TX and the XCVR RX.2. Output Voltage Swing (VOD)
Confirm that the TX output signal meets the input specs of the RX. If possible, performing a signal integrity simulation is highly recommended to validate this.3. AC Coupling and Termination
With AC coupling in place, you may enable the on‑chip termination at the RX side.4. CDR Lock Requirement
Since you are using the XCVR RX, sufficient signal transitions are required for the CDR to lock properly. You may consider using an encoding scheme such as 8b/10b.5. Initial Bring‑Up Test
It would be helpful to start with a simple single‑channel test design to perform an initial check and verify that the link can be established successfully.Please let me know if you have any further questions. Thank you.
