DSPS can work without cts and rts?

Hi,all.

I saw a modulel dsps pcb .DSPS can work without CTS and RTS ,test out that the sleep electric current is performed.
So ,that is to say,the RX interrupt can wake up the 14580 when 14580 in sleep.
I test the function follow without CTS,RTS ,open sleep.
static void app_sleep_prepare(sleep_mode_t *sleep_mode)
{
if(*sleep_mode == mode_sleeping)
{
#if (UART_SW_FLOW_ENABLED)
if (!uart_sps_sw_flow_off())
#endif //UART_SW_FLOW_ENABLED

#if (UART_HW_FLOW_ENABLED)
if (!uart_sps_flow_off())
#endif //UART_HW_FLOW_ENABLED
{
*sleep_mode = mode_idle; //(A)
}
else
app_sleep_flow_off = 1; //*for uart realtime*// //(B)
}
}

the result is :
static void app_sleep_prepare(sleep_mode_t *sleep_mode)
{
if(*sleep_mode == mode_sleeping)
{
{
*sleep_mode = mode_idle; //(A)
}
// else
app_sleep_flow_off = 1; //*for uart realtime*// //(B)
}
}

如果我盾(B),leave (A) to used ,the project can get RX data but not enter sleep.
when debug code in 14580,5~7second delay ,can get rx data and tx data to PC.

but when I shield (A),only leave (B) to used ,the project can not get RX data.

How to handle sleep function to realize DSPS work without CTS and RTS?
can you give me some suggestions.

thanks.