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Altera_Forum
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15 years ago

A problem on I2C, which may cause by the pin to pin resistance on the emulation board

Dear Sir, I met one problem as the attachment. The voltage drop is supposed caused by the pin to pin impedance, I guess. Because pin to pin resistance is about ony 30K to 40K Ohms which is...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

Hi Johannes,

You're right. The high pull-up is one of the problem. But I'm using a FPGA

internal pull-up. I'm not quite sure how large it is. I may only estimate it

based on the voltage level I could see. I don't know if it is able to be set. Anyway, from the point of view, to solve the problem, I may only use

an external pull-up. Do you think so? Thank you!

Peter Chang