ted wrote: ↑
Wed Jan 03, 2018 1:03 pm
Will disabling those lines make microcontroller less busy ?
I guess not much.
There is a danger to my not responding to this statement as it may be read and interpreted by a non-hardware user as meaning that within the uC, disabling peripheral interfaces will/would make the uC run faster. This is not the case.
If one studies the STM32 architecture document, one will note that the microcontroller has internal buses that connect various subsystems. Disabling a subsystem "may" reduce the chip power usage, but generally subsystems that are not utilized are not initialized and configured, so power dissipation of non-used peripherals should be minimal.
What does make a microcontroller "busy" is the start-up/initialization code and then user code that exercises the various peripheral activities. Some peripheral devices such as PWM consume bandwidth when they are configured but afterward do not consume any user execution time unless something is changed by user code. Of course, when PWM is active, electrical power is consumed because that device is active and clocking to an output pin.