Stanford Research Systems SIM910 Operating Manual page 33

4.1 Circuit Discussion
SIM910 JFET Preamp
Amplifier overload
Incoming serial data
Front-panel button press
The fast start-time of the RC-oscillator ensures that incoming se-
rial data will be correctly decoded by the microcontroller's UART,
even when the clock is started by the serial start bit of the incoming
data. When the microcontroller has completed all pending activity,
it drives the STOP signal high (pin 24 of U405), e ectively halting its
own processor clock. In this way, the SIM910 guarantees no digital
clock artifacts can be generated during quiescent operation.
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