Enable interrupts

[Micilera]

Sirs,
Argument: Enable Interruputs
Platform: Arduino Due
Version: v4.3.9 and v4.4.0

File: \src\platform\HAL_DUE\HAL_timers.cpp::HAL_timer_start()
I see the following:

TC_Start(tc, channel);

// enable interrupt on RC compare
tc->TC_CHANNEL[channel].TC_IER = TC_IER_CPCS;
tc->TC_CHANNEL[channel].TC_IER = ~TC_IER_CPCS;

// Finally, enable IRQ
NVIC_EnableIRQ(IRQn);

Looking at some other examples and there are many, I see:

// Enable the RC Compare Interrupt...
t.tc->TC_CHANNEL[t.channel].TC_IER = TC_IER_CPCS;
// ... and disable all others.
t.tc->TC_CHANNEL[t.channel].TC_IDR = ~TC_IER_CPCS;

and that seems to me much more reasonable.

Could you please explain how does your solution work and why?
Best Regards,
Micilera

[Micilera]

I'm sorry that you didn't give us an explanation about your previous
approach of enabling interrupts, but I am happy that you made some little
changes at the code in this area. A little step ahead, but very appreciated.
Very good.
Now I see for the Arduino DUE platform in the same method
HAL_timers::HAL_timer_start() at line 131/132:
// Disable timer interrupt
tc->TC_CHANNEL[channel].TC_IDR = TC_IDR_CPCS;
and few lines later, at line 150/151:
// enable interrupt on RC compare
tc->TC_CHANNEL[channel].TC_IER = TC_IER_CPCS;

So, the disable bit (TC_IDR, Interrupt Disable Register) is set, but
also the enable bit is set (TC_IER, Interrupt Enable Register).
Who will win?
So your approach is very interesting and I would kindly ask you if
you can give us some more details as an expert.
Best Regards,
Micilera