systick handler keep pending on stm32h7 board.

[sheng yang]

I made a project with stm32h7 board, and use pemicro multlink to debug it under keil. I found it keep in systick handler pending but no active.

I checked systick module register as:

the counter is changed.

and then I checked SCB releate registers as

and the interrupt handler addr is as

matched with vector config as:

I don't know where is wrong ?

[TDK · Accepted solution]

Only so many reasons why an interrupt is not happening. Go down the list and verify them all:

• Interrupts need to be enabled globally (they are by default, use __enable_irq()).
• SysTick interrupt needs to be enabled (in SysTick->CTRL)
• Execution cannot be in an equal or higher priority interrupt (print out SCB registers).

Viewing values in a register viewer (e.g. the SFR window in STM32CubeIDE) will be easier to navigate than viewing raw memory and translating.

[sheng yang]

1. I have checked SysTick->CTRL = 0X7 so SysTick interrupt has beed enabled. 

2. Execution cannot be in an equal or higher priority interrupt (print out SCB registers)  I wonder which register do you mean ? and I have print these registers in the picture below.

3. Interrupts need to be enabled globally (they are by default, use __enable_irq()) I will check this later with PRIMASK , FAULTMASK, BASEPRI..

[TDK]

> 2. Execution cannot be in an equal or higher priority interrupt (print out SCB registers)  I wonder which register do you mean ? and I have print these registers in the picture below.

Mainly SCB->ICSR, which contains VECTACTIVE. Should also get this information by looking at the call stack.

[sheng yang]

I'm sorry replay so late, later I found the reason is that I disabled irq before with.

CPSID   I