My colleague is facing a problem regarding the u-boot procedure.
When requested, our system needs to enter “deep sleep mode” during u-boot process.
The system needs to wake up through the interrupt at the rising edge of “GPIO3_IO27”.
Before the system goes to "deep sleep mode", DDR is set to “self-refresh,” and the interrupt program and the vector table are copied to IRAM.
We have designed so that when “GPIO3_IO27” interrupt occurs the interrupt program in IRAM will start.
But, this mechanism does not work. In other words, the system does not wake up at the rising edge of “GPIO3_IO27”.
We are afraid there are basic misunderstandings in our thought.
We would appreciate any comments regarding the above procedure.