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Altera_Forum
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13 years ago

Cyclone III -- IO port in VHDL help

I'm writing a small code to simulate the I2C. In VHDL, the "sda_io" is defined as an IO port. I thought this simple statement should work: sda_io <= '0' when drive_sda = '1' else (other => '...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
13 years ago

Check the synthesis results. Once upon a time, the recommended syntax for a tri-state was to have the 'Z' first, i.e., 


io <= 'Z' when (io_oe = '0') else io_out;

But that could have been 'fixed' in newer versions of the tools.

Cheers,

Dave