Honored ContributorHello,
I can see in the Arria V handbook that we can have 3 settings for LVDS TX I/O. 0, 1 and 2. I am wondering what these would correspond to on the board assuming 100ohm termination at the far end. Please note, that I am not asking for the xcvrs. Rather the LVDS i/os. Anyone know where I can get this information? I cannot find it in the datasheet as well. TIA. Best regards, Sanjay
Honored ContributorAs far as I know, there are no such setting. User only required to set differential at the RX side.
Also the 0 1 2 seems like the drive strength for normal GPIO output....Honored ContributorHi Sanjay,
The VOD will large be dependent on the board setup. It is recommended for your to run IBIS or Hspice simulation to determine the VOD and VID in your setup.Honored ContributorSanjay,
I think you are referring to the Programmable Differential Output Voltage (VOD) that is in the Quartus assignment. It is actually a pre-emphasis that increases the amplitude of the high-frequency component of the output signal. So you will see a boost at the at the initial part of the signal to be slightly higher, so that when it reaches the Rx side, it will still have a nice eye opening. You need to test out on a simulator with IBIS or Hspice to know what setting would give what eye opening on the Rx.Honored ContributorYou can find the links to IBIS and Hspice download page at here:
https://www.altera.com/support/support-resources/support-centers/signal-power-integrity.htmlHonored ContributorThe Arria V LVDS VOD specification is from 0.247 to 0.6V. You should expect your VOD within this range. You can refer to Table 19. Differential I/O Standard Specifications for Arria V Devices in Arria V device datasheet for further details.
