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Altera_Forum's avatar
Altera_Forum
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12 years ago

ISR driven UART is missing characters (even at 9600bps... same prob at 230400)

Any ideas on what I'm missing here that is causing me to miss characters? I'm interfacing to a device that shoots out RS232 packets (up to 200 per second if the bps can handle itI can select t...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
12 years ago

Here is a screenshot of the problem occuring. The green trace is the input waveform at 9600bps and the ISR line is a logic analizer pod running on the line the ISR drives high and then drives low when it exits... so, not a lot of time is being spent there. Around 80% of the characters are captured into the circular buffer. There is a similar happening at 115200.