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This program have three I/O functions that connect to UART driver via ioctl: (read(), write() and select()), but select() and write() change process stat to sleep mode until system don't receive or transmit all information via UART, the process awake when I/O task is completed. "select" function is used to prevent that reads read function can be blocked when there data aren't data avaliableavailable.<br>The next captures are do it images (program with GPIO debug mode gpio enable and 300 bauds speed) show when program are in sleep/run mode . Blue=UART1, Violet=write function time and Green=select function time.<br>
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