Cyclone 3 LVPECL

[Altera_Forum]

Hi, 

 Can the Cyclone 3 family trasmit LVPECL?   Bob

[Altera_Forum]

--- Quote Start ---  Hi,   Can the Cyclone 3 family trasmit LVPECL?   Bob  --- Quote End ---    Check the Cyclone III handbook: LVPECL is only supported on dedicated clock inputs if VCCIO = 2.5V. So no LVPECL transmitters.  -- Ton

[Altera_Forum]

Thanks for the info

[Altera_Forum]

The data sheet says that in order to use LVPECL, VCCIO must be +2.5V. Only the dedicated clock inputs can be used to receive LVPECL. I cannot find which dedicated clock pins go with a specific I/O bank.  

Very confused.

[Altera_Forum]

--- Quote Start ---  I cannot find which dedicated clock pins go with a specific I/O bank  --- Quote End ---  . ??? The information can be found in many places, e.g. Quartus Pin Planner tool, Quartus pinout file, Cyclone III device specific pin tables.  Regarding your original question, it's true, that the Cyclone III hardware manual clearly states LVPECL only supported for dedicated clock inputs. I can't see a clear reason for this restriction however, you should have no problems to generate LVPECL compatible levels from a differential output with a resistor network, similar to LVDS_E_3R IO-standard, at least for a specified fanout.