Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

cycloneIII EP3C25E144 I/O pins

I'm using CycloneIII EP3C25E144 FPGA for my design .In cycloneIII brochure the no of I/O's available for the specific FPGA is mentioned as 82 but in the pin description table I could find only 65 I/O...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

--- Quote Start ---

Please let me know if I can use the CLK[0..15] pins as optional I/O pins.

--- Quote End ---

They can be used as general input pin. Unlike standard I/O pins, they don't have a weak pull-up or hold option, so they shouldn't be left unterminated.

Generally, the pin-out files for individual Cyclone III types have the most detailed information about functionality of each pin. Quartus Pin Planner also knows about available pin features.