STM32 WWDG interrupt firing when not configured

Question

I have an application that I am porting from the Keil IDE to build with the GNU toolchain due to license issues. I have successfully be able to set up, build, flash and run the

Answer 1

I had a very similar problem when merging two projects generated separately by STM32CubeMX for an STM32F2XX processor. One project was using the Ethernet peripheral, while the other was not. Besides that one difference, the two projects used the same set of peripherals.

After integrating the two projects together by manually copying files, the application would end up in the WWDG_IRQHandler after starting the first task (when interrupts are enabled for the first time). I first confirmed that the WDGA bit of the WWDG register was indeed not set and, therefore, that the WWDG peripheral was disabled. Next, I verified that the interrupt vector table was initialized correctly. Finally, after several hours of digging, I realized that I had not defined the ETH_IRQHandler function in stm32f2xx_it.c, which provoked the Ethernet interrupt to be handled by the default handler, masking itself as the WWDG_IRQHandler -- likely due to optimization.

Answer 2

I had exactly the same error as OP (apparent WWDG interrupt, but actually the HardFault_Handler firing) when porting an example for the STM32F3 Discovery board to compile in CooCox CoIDE 1.7.7 with STM32Cube F3 libraries (v1.1.0). The code ran fine as long as I didn't try using any interrupts, but as soon as I turned on the SysTick timer interrupt, the HardFault exception tripped.

The problem was that I had neglected to include the stm32f3xx_it.h and stm32f3xx_it.c files in the project. Their absence wasn't causing any compiler warnings/errors. Once they were compiled & linked in, the code with interrupts ran fine.