Forum Discussion

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

pull up/down resistors

Hello people, I work on some project where I need to control some device via cyclone II FPGA (DE2 board). Using some FPGA pins I control device and using other FPGA pins I monitor the response ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
17 years ago

It depends on your application. The larger the pullup resistor value is, the slower the rising and falling edges are. If the you think that you need pull-up or pull down resistors to set outputs to hight or low logical level for safety during power-up because I/O pins remain tri-stated during power-up, I think that you have to.

Anyway, in Quartus-II, you can use the assignment editor to set output to weak pull-up.