Hi, Kien,
If your code always enters void _EntryPoint(void) function when you run your code, it means Reset event happens, the Reset sources may be from Power on reset, watchdog reset, core fault reset...
Firstly, pls disable the watchdog with the code:
#define DisableWatchdog \
COP_CTRL &= ~(0x2);
int main(void)
{
DisableWatchdog;
.......................
}
Because the watchdog is enabled in default after Reset.
If it can not solve your issue, it is a bit complicated to find out the Reset source.
BR
XiangJun Rong