Honored ContributorHi,
TQ is giving me this message when I run the rskm_report. Info: No dedicated SERDES Receiver circuitry present in device or used in design I do have an LVDS receiver instantiated on my design so I'm not sure what I'm missing. Regards, Rob
Honored ContributorI should have mentioned I will be using either a Cyclone 3 or 4 device.
Honored ContributorI believe we need to separate between the concept of lvds and serdes.
lvds is about the io voltage aspect (Rx or Tx) serdes : serialser/deserialiser with associated pll etc.Honored ContributorRight, I have a SERDES receiver implemented using a PLL. Actually I use the ALTLVDS_RX MF
Honored ContributorIn that case, well you know you are using it so either the tool is lieing or that the serdes is implemented in another way ! I actually have the same warnings in my system with 32 serdes instantiated (serialisation factor 2:1) but Timequest says no serdes used. I just ignore it.
Honored ContributorI'm trying to figure out my RSKM by using TQ and the rskm_report command. So I suppose that if TQ won't report it, then I have use the Tsu and Thld times reported by TQ to calculate the RSKM.
RSKM = (TUI - SW - TCCS)/2 TUI : Time Unit Interval SW : Sampling Window TCCS: Transmitter channel to channel skew Tsw = Tsu + Thd + PLL jitterHonored ContributorI just checked the resource section and realised that in my case the serdes were implemented as ddio.
Honored ContributorHonored ContributorRob, The report_rskm and report_tccs TimeQuest reports are only valid for devices that have the SERDES implemented in hard silicon (e.g. Stratix families). The Cyclone families use DDIO and logic to implement the SERDES, and therefore cannot use these commands. In the Cyclone families, these interfaces are times using the standard micro-model timing just like any other standard I/O interface.
