How to enable and disable all interrupts ?

[Milan]

Hi Team,

Is there any way to enable/disable all interrupts? Will BLE connection get disconnected because of this? If yes the what are the possible ways to maintain the connection?

[RK]

1. Is there a way to enable/disable all interrupts. Yes, set primask. There's a __disable_irq() and an __enable_irq() macro to do that .. however
2. Will BLE connection get disconnected because of this? Yes, it will, perhaps not instantly, perhaps not every time. The longer you have them disabled, the more likely the SD will break that time but even if you have them disabled for a really, really short time, it will eventually and randomly break. So don't use the __disable_irq() or attempt to disable all interrupts. It will not work.
3. What are the possible ways to maintain the connection? Don't disable all interrupts is the way to maintain the connection. You can use the sd_nvic_critical_region_enter()/exit() functions to turn off all interrupts the softdevice isn't using. That is the most you can do.

What problem are you actually trying to solve?

[RK]

Bottom line - you can't do it. The max period you can disable interrupts is ZERO, you may not disable interrupts when the softdevice is running, not for 1ms, not for 1us, not at all, not ever. That is the contract you make with the softdevice. You cannot do time-sensitive operations with the softdevice running. Period.

I wrote this post a week or so outlining how someone could try to use the Multiprotocol Timeslot API which gives you occasional, irregular, small slots of time during which you can do what you like, to bitbang out 1 or 2 or 3 characters over a UART, then shut everything down and wait for the next time it gives you a slot and do the next few. That's theoretically possible, it would be very hard to implement, you'd get very irregular transmission. My eventual suggestion was to use a separate UART chip.