Forum Discussion

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

Weak pull-up resistors

Hi everyone! I enabled weak pull-ups for the input and output pin (cyclone II device). But when I measure the voltage on these pins, on the input pin is 3V and on the output pin is 0V. Shouldn...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

According to the datasheet, the peripheral that I want to connect to my fpga should have all 4 SPI signals pulled high with internal pull-up. But when I power the peripheral up, only SDO (which should be connected to MISO) is high, the other signals are low. I wanted to make sure that pull-ups in the fpga are on initially, so that I do not cause any damage to the devices when I connect them because I don't know if the pull-ups are on initially in my peripheral.