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Altera_Forum's avatar
Altera_Forum
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13 years ago

Creating a bidirectional bus

I want to connect a USB chip (FT245R) to a CPLD. To do that I need a bidirectional 8-bit bus. I thought I could declare the pins to be bidirectional and with a mux, read to or write from the pins as ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
13 years ago

I understand and that's very good advice. I have tested with MyHDL and ModelSim the module that deals with TXE and outbus and the module that deals with RXF and inbus. TXE and RXF are mutually exclusive in that only one can be true at any time. The code I am working on now, which requires the bidirectional bus, is additional test code to be downloaded into my device to determine if these modules will actually communicate with the USB device (FT245R). I'll write some code to test the bidirectional buffer stuff with ModelSim.

Thanks very much for your help.

Thanks also to FvM for the comment regarding the inout declaration.