# System Tick Problem

Question asked by asl.sean on Feb 24, 2014
Latest reply on Feb 25, 2014 by fm
Hi ,

I am using STM32F429 discovery. The system tick is suppose to produce an interrupt every 1ms.

However, i have gotten 3.12ms instead. Did i make a mistake ?

`int main(void)`
`{`
`    ``Init_LEDPanel();`

`    ``// Pulsing at 1msec per interrupt`
`    ``SysTick_Config(SystemCoreClock/1000);`
`    ``while (1){}`
`}`

`void SysTick_Handler(void)`
`{`
`        ``GPIOE->ODR ^= GPIO_Pin_4;`
`}`