Dwayne Reid wrote:
> At 12:35 PM 8/2/2010, Isaac Marino Bavaresco wrote:
>> The problem with the U(S)ARTS of most PICs is that they need the
>> clock to be running. The receiver samples the incoming signal
>> synchronously with the clock. If the clock is not running then the
>> USART will not see the signal.
>
> That may be the case on some PICs but does NOT appear to be the case
> for the 16F77.  We are currently putting the PIC to sleep (clock is
> stopped) and it wakes after receiving 9 clock edges fed into the TX
> pin (which is the synchronous slave Clock pin).

Right, because you were using it in synchronous mode where the clock comes
in with the data.  Isaac is correct when the module being used as a UART,
but not as a USART.

Some newer PIC UARTs also have a wake up feature.  I've never used it, so I
don't remember if the first byte is lost.


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