Altera_Forum
Honored Contributor
14 years agomax v tri-state i/o
Hi, I need to use the tristate i/o feature of max v and can't seem to find the i/o block in the megawizard library. Anybody know how to use the feature ?
Dave, will the Fitter automatically map my enable signal to the output enable of the i/o block ? Because in the pin assignment editor i don't see an option.
Thanks. --- Quote Start --- Then you would drive the signal with a tri-state that has an output-enable, i.e., in VHDL bidir <= 'Z' when (enable = '0') else output; and you can read bidir as an input at any time; when enable = '0' you are reading what is driven onto the pin by the external device, and when enable = '1', you will read what you are driving on 'output'. You can turn on the 'weak pull-up' or 'bus hold' on the pin for bidir so that it is always in a valid logical state. Cheers, Dave --- Quote End ---