configuration change when the code have run

Hi,all,

In project DSPS 3.150.2 peripheral.
I have close sleep and close flow control .

I want to change configuration when the code have run,
configuration need to been chang is: baudrate, the MAC.

I have try to realize this goal.but is not get success.
get start baudrate is 115K200 ,the set is :
uart_sps_init(9, 3); //#define UART_BAUDRATE_115K2 9
in function
void periph_init();
then in code ,I set
uart_sps_init(17 , 3); //#define UART_BAUDRATE_57K6 17
but the baudrate is not changed,and the UART function is not work,because is not print information any more.

The mac i have change in function
void nvds_read_bdaddr_from_otp()
memcpy(&dev_bdaddr, BD_ADDR_ARRY, 6); //BD_ADDR_ARRY is my MAC
I Stop Advertising use app_adv_stop(),
then Start Advertising use app_adv_start(void);
But the MAC is not changed because the phone scan result is not change.
So,i used app_reset_app(); but also not make it.

please help me.

thanks.