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Altera_Forum
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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
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14 years ago

Hello Dave,

Thanks for the suggestion. When I drive it high, i.e. instead of 'Z' I write '1', the pin is initially 3.3V.

What I also found out is that for SOPC builder components, I cannot define initial states like that. For instance, when I use SPI interface with Clock polarity = 1, Clock phase = 1, after programming the device, only SSn and SCLK are 3.3V. MISO is 3V and MOSI is 0V. MOSI becomes 3.3V in the idle state only after sending a byte via SPI. I have to figure out now how I can set all the lines to be 3.3V from the beginning.

Nikola