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Altera_Forum
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12 years ago

Design working in simulation not on real device

Hi, I am trying to design my own implementation of I2C on a Cyclone II EP2C5T144 The design works in simulation but once programmed on the chip, it acts strangely, only a few bits are tran...
Altera_Forum's avatar
Altera_Forum
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12 years ago

There are at least two points:

- 'H' state isn't synthesizable. I2C bus signal must be driven to 'Z' or '0' and use external pull-up resistors. Driving SCL in a push-pull manner is only O.K. if you are sure that the connected slaves don't utilize clock stretching.

- external signals read into your state machine must be synchronized, by state-of-the-art double registered.