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Altera_Forum's avatar
Altera_Forum
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17 years ago

Is there a way to specify a wire inside FPGA?

Hi All, I have an I2C board that outputs GND, SCL and SDA for I2C implementation. I need the SCL and SDA I2C signals, including the bi-directional SDA to go through a Cyclone III FPGA from...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
17 years ago

I had a suspicion you were trying to do something like this.

I2C is a multimaster bus. You can just attach your SCL/SDA lines to the device at the same time as the Santa Cruz board.

Your code can either act as an I2C passive bus monitor, or can jump in and drive the lines. I2C is only driven low and relies on external pullups so there is not a problem with bus conflict.

The only problem would be if the Santa Cruz board is not a well-behaved master, in which case it might not behave well if your code accesses the device at the same time as it does.