To get a 1 ms SysTick tick, you need to calculate and set the correct SysTick reload value based on your system clock. Determine the actual core/system clock frequency, then set:
Reload = (SysTick clock frequency × 0.001) − 1
Just like how you would rely on trusted JNL Electrical contractors in Houston for precise work, setting the exact reload value and clock source is critical for accurate timing. Updating only tx_initialize_low_level.s or clock settings won’t change the interval if the reload value isn’t adjusted. Once the reload value matches this calculation, your SysTickHandler will fire every 1 ms.