topic two system tick timers in CPU0 in lpc55s69 in LPC Microcontrollers

two system tick timers in CPU0 in lpc55s69

binjun-charles_ — Mon, 23 Mar 2020 05:26:34 GMT

Hello All

As we know, there are 2 system tick timers in CPU0. I am trying to initialize secure one in secure world and non-secure one in trustzone example project(hello-world and My IDE is IAR 8.40).

1. The secure one is working if i call SysTick_Config in secure world.

2. The non-secure world enters hard fault if i call SysTick_Config in non-secure world. I debug the non-secure world code and it shows that SysTick_Config use secure address to configure the system tick timer. (why does it not use Systick_NS address? )

Anyone could help me to initialize 2 system tick timers separately in different worlds?

Re: two system tick timers in CPU0 in lpc55s69

xiangjun_rong — Mon, 23 Mar 2020 08:11:23 GMT

Hi, BinJun,

Can you post your code so that we can have a review?

XiangJun Rong

Re: two system tick timers in CPU0 in lpc55s69

binjun-charles_ — Mon, 23 Mar 2020 08:30:08 GMT

i used a example code in SDK_2.7 -- \boards\lpcxpresso55s69\trustzone_examples\secure_gpio.

In the non-secure world project, i call SysTick_Config(USEC_TO_COUNT(5000U, DEMO_SYSTICK_CLK_FREQ)) in main() entry. Then program enters hard fault.

Re: two system tick timers in CPU0 in lpc55s69

binjun-charles_ — Mon, 23 Mar 2020 13:34:19 GMT

Also i have tried the code below in secure project

//configure secure systick

SysTick_Config(MSEC_TO_COUNT(1000U, DEMO_SYSTICK_CLK_FREQ));

//configure non-secure systick

SysTick_NS->LOAD = (uint32_t)(MSEC_TO_COUNT(2000U, DEMO_SYSTICK_CLK_FREQ) - 1UL);
SysTick_NS->VAL = 0UL;
SysTick_NS->CTRL = SysTick_CTRL_CLKSOURCE_Msk | SysTick_CTRL_TICKINT_Msk |SysTick_CTRL_ENABLE_Msk;

The code seems working(non-secure systick working, but frequency is not same as value i set).

However secure systick is working after configuring non-secure one. How can i configure these 2 system tick timers separately to make them working in different worlds.