Is it a feature of Cortex-M series MCUs to be able to wake from a low power mode (sleep or deepsleep or other MCU specific modes) with interrupts configured but disabled?
The mechanism for entering the low power mode is executing WFI instruction.
The MCUs I have used from STM and Renesas, wake from the low power mode via an interrupt if the interrupt is configured correctly and even if all interrupts are disabled via the cpsid instruction.
I am trying to determine is this is what I should expect on all Cortex M series based MCUs or just specific to certain MCU vendors.
Every ARM Cortex-M will work this way as long as you use PRIMASK to disable ALL interrupts. This is what __disable_irq() from CMSIS does. According to the docs, raising priority with BASEPRI will not cause an interrupt with insufficient priority to wake the chip.
See here - http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0552a/BABFEFIG.html
Operation
WFI is a hint instruction that suspends execution until one of the following events occurs:
- a non-masked interrupt occurs and is taken
- an interrupt masked by PRIMASK becomes pending
- a Debug Entry request.