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Altera_Forum's avatar
Altera_Forum
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16 years ago

Using LVDS

Hello, Could anybody please tell me how I can use the HSTC Connectors to communicate between two DE3 Boards? I tried using bidirectional buffers to send/receive data over the pins, but tha...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

Thanks Frank! I apologize for my late reply. I did assign a VCCIO of 2.5 V to the I/O Groups using LVDS. I can cross check this with the LEDs by the power switch.

I am puzzled as to why this will not work. Do I need to assign clock signals to the CLKOUT/CLKIN Signals?

I get two warnings:

--- Quote Start ---

Pin "SENDING" is a differential I/O pin but does not have its complement pin. Hence, fitter automatically created the complement pin "SENDING(n)"

Design has one or more differential I/O pins that do not connect to SERDES receiver or transmitter -- changes to this connectivity may affect fitting results

--- Quote End ---

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An unexpected event occured when I stacked the DE3s one atop the other. This causes all the HSTC's to connect, whether one intends to use them all or not. This results in not being able to use the DDR interfaces anymore, because the HSTC-B and the DDR interface share the same pins. However, one can mount the boards such that only one HSTC pair connects. Not quite the picture I had in mind.