Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
11 years ago

Problem of receiving data from UART RS232

Hello everyone. I am now working on a project and it has to receive data from the COM port (RS232). I have written a receiver in VHDL. However, the code does not always receive correct data byte ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
11 years ago

The data signal can change outside the clock edge.

The datain signal becomes metastable, it is neither '1' nor '0'. You need it to be stable.

You can do this very simple, by clocking it trough at least two registers. (Search the web for metastability for more info on this.)

In this way your data may not be correct, but it is the same troughout the entire circuit.