Hi everyone,
I need help about NMI that seems to freeze mu µC during power on.
I use a cortex M4 ( K64 from NXP/Freescale ). On the board I use, the NMI is connected to a push button.
If I don't press the NMI button, my software run.
If I press it (NMI active) and power up the board, my software doesn’t run (I got nothing on UART and nothing on the LEDs).
So I try to put a probe (UlinkPro) to see what’s happening.
If I press the button, then power on the board and then try to run a debug session, the probe doesn’t see the internal JTAG module of the µC. SO I cannot see what’s happening.
Does the NMI stop the internal start-up? Does it create an internal reset?
My interruption clear Enable and Pending registers (NVIC_ICER & NVIC_ICPR) and un-connect NMI (I put the external pin in GPIO mode, like that I select when I re-enable the NMI). I also try to put an infinite loop in order to exclude register error du to ISR call.
I someone can help me.