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SAM7S256 demo stops Tx to USART0

Posted by Darrik Spaude on September 22, 2006
When using the SAM7S256 demo source (which has a task created for Tx and Rx on USART0), it is possible to cause the Tx task to stop. The way I caused this failure was to hold down any key (yes, the "any key") on the keyboard for long periods of time. Sometimes I had to release the key and then hold it down again. However, it doesn't take long before the transmitter stops transmitting to the serial port.

If someone has one of the other serial examples running on a different processor (or an Atmel processor), would you try to see if you can cause the RTOS to stop sending data? In the example demo a string of characters (A through X) is output continuously.

What I am hoping is that there is a simple solution to this problem. I will eventually need a serial port that can transmit and receive data at 230400 baud simultaneously and without error.


RE: SAM7S256 demo stops Tx to USART0

Posted by Richard on September 22, 2006
The serial port demos are inefficient as their purpose is to test the task switch from ISR mechanism. They do not make use of FIFO's, DMA's etc and are not intended for application use. They cause a context switch on every character.

RE: SAM7S256 demo stops Tx to USART0

Posted by Darrik Spaude on September 22, 2006
Do you know of any examples that use the FIFO and DMA?

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