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Altera_Forum's avatar
Altera_Forum
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11 years ago

I2C Protocol help

Hi, I am new to VHDL. I am trying to implement an I2C master for practice (synthesizable code). At the moment , I have code written to send the start bit and then 8 data bits. The SDA should chan...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
11 years ago

There's nothing against writing an I2C master interface from the scratch, but to do so, you would start with studying the NXP I2C specification, particularly the required signal timing. Then implement hierarchical state machines for bit timing, byte read/write, overall control.

SDA must be a bidirectional inout port, SCL can be output only for simple masters that don't support clock stretching. To tristate SDA, you'll assign 'Z' state to it.