wake up from stop mode on usart interrupt: do I need to configure EXTI?

[bruzzim]

Posted on February 26, 2010 at 12:31

wake up from stop mode on usart interrupt: do I need to configure EXTI?

[Tomas DRESLER]

Posted on May 17, 2011 at 13:41

In STOP mode USART clock is off, too. To detect incoming packet, you have to use EXTI wake-up as this is the only suitable peripheral able to wake your MCU up.

Next, you have to consider that STM32 will wake up on 8 MHz clock and it will take few ms to switch on HSE and PLL again => the first byte may be wrong and your protocol has to count with that.

[bruzzim]

Posted on May 17, 2011 at 13:41

Thanks again, edison.

[Barbie]

Posted on May 04, 2013 at 09:31

So if I get it right. The UART frame itself can't wake up the MCU from stop mode. I need to make same kind of HW line taht give me pulse on GPIO when I receive UART frame. Is it so?

Bar.

[Tesla DeLorean]

Posted on May 04, 2013 at 16:33

You're bigger problem is that it will miss the first byte, at least.

I seem to recall one of the F0/F3 seminars of a low power mode where the function of the USART was maintained.

The alternative would be a method using a RTS/CTS based handshake to wake up the part first, and then indicate it could receive new data.