First of all, sorry for my bad english, but it´s not my mother language... (i speak spanish).The thing is, in the University (FRBA UTN, Electronic Engeniering) we are trying to start a few new projetcs, involving hardware interaction. We actually have 4 DE1 kits ready to use. The problem is, that we don´t know the voltage and current level for the GPIO ports for output and input usage, and burning one of the kits just for testing it´s out of the question (unless i want to change of carrer :p).... so, anyone have real information of the ports parameters? I prefer real testing results... Thanks in advance!!
Do you mean that the components between the GPIO header and the chip don´t change anything?Sorry, but the electronics never worked that way... If there is ANYTHING between, it will gone a change specificactions (more or less, but there is always a change)... Anyways, real tests comments are far better...
The expansion header circuit is completely described in the DE1 user manual. There's just a 47 ohm series resistor between connector and FPGA pin. With Cyclone II, PCI diodes can be enabled for part of the IO-pins (left and right banks) additionally, but they don't provide protection before user mode is started.
GPIO pins are finally connected to pins on the Cyclone II fpga on DE1 (via resistors). The final voltage & current driving stats can be found in the DC characteristics section in Cyclone II handbook [http://www.altera.com/literature/hb/cyc2/cyc2_cii5v1.pdf].In DE1, I believe the cyclone II GPIO data pins work @3.3V (when configured as LVTTL) with 40mA max sourcing current & 25mA max sinking current. But please don't take my word for it; do check with the handbook first.