S9KEAZN64 doesn't run code from flash after power reset

[vitaliharudka]

Hello. I have make a custome board with S9KEAZN64 MCU and got next trouble. I am using segger j-link edu for programming and debug. I wrote software led blink for test and start debug it. All work correcty but when i stop debug and reset power it doesn't start again. Code running from flash and i checked flash memory via segger. Binary are there. I tried to make reset pin low and high back but it doesn't help. But it is possible to start it via J-Link tool(button named start mcu or similar). What can be wrong? Thanks.

[jingpan]

Hi VITALI,

S9KEA boot up sequence is simple and directly. When the processor exits reset, it performs the following:

• Reads the start SP (SP_main) from vector-table offset 0
• Reads the start program counter (PC) from vector-table offset 4
• The Link Register (LR) is set to 0xFFFF_FFFF.

You can see these words in reference manual 6.2.2.

Maybe you can check 4 point:

1. Is there a 4.7uF or above capacitor on VDD. Without this cap, latch-up may happen.

2. May it caused by improper watchdog setting?

3. Is hardware design or welding ok?

4. Is the project setting well? Can other demo code run correctly.

Please try this driver library:

https://www.nxp.com/webapp/sps/download/license.jsp?colCode=FRDM-KEXX-Driver-Library-Package&locatio...

This is for KExx, but it also can run on KEA. They are all same.

Please also try device demos in https://www.nxp.com/products/processors-and-microcontrollers/arm-based-processors-and-mcus/kinetis-c...  

Regards,

Jing

[vitaliharudka · Accepted solution]

It was required to off NMI. While debugging it off automatically but after power reset it's turn on and mcu stuck in interrupt.