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Altera_Forum
Honored Contributor
17 years agoStratix III LVDS OCT
Hello! I am using stratix III and I have a few questions about LVDS and OCT in stratix III and I/O buffers. 1. If we want to use dynamic termination, can we use differential mode? a. ...
Altera_Forum
Honored Contributor
17 years agoBy design, BLVDS is using a party line, 100 ohm terminated at both ends. This is the only way to achieve impedance matching in a multidrop bus topology. Dynamic OCT wouldn't be helpful in this situaion.
I understand, that you intend a bidirectional point-to-point connection, in this case differential dynamic OCT would be an option. I think that it's provided with Stratix III, but no tri-statetable true LVDS driver. Pseudo-differential operated single-ended buffers with serial termination have to be used instead. P.S.: For Stratix III, Quartus doesn't offer a BLVDS I/O standard in Pin Planner. Diff. SSTL has to be used instead. See AN522: --- Quote Start --- In Stratix III and Stratix IV devices, BLVDS interface can be implemented using 2.5-V Differential SSTL Class I or II, depending on the current strength requirement. --- Quote End ---