DSPS software reset issue

In the DSPS software of DA14580, do the software reset use the code shown below. But it doesn't work.
Who can help me to find the reason.

void Start_run_user_application(void);
__asm void sw_reset(void);

/**
****************************************************************************************
* @brief sw reset
****************************************************************************************
*/
__asm void sw_reset(void)
{
LDR r0,=0x20000000
LDR r1,[r0,#0]
MOV sp,r1
LDR r2,[r0,#4]
BX r2
}

/**
****************************************************************************************
* @brief Run the user application after receiving a binany from uart or reading the binary from a non volatile memory booting
****************************************************************************************
*/
void Start_run_user_application(void)
{
volatile unsigned short tmp;

if (*(volatile unsigned*)0x20000000 & 0x20000000)
{
tmp = GetWord16(SYS_CTRL_REG);
tmp&=~0x0003;
SetWord16(SYS_CTRL_REG,tmp);
sw_reset();
}
tmp = GetWord16(SYS_CTRL_REG);
tmp|=0x8000;
SetWord16(SYS_CTRL_REG,tmp);
}