使用NuMaker-IoT-M487没看到有wake up的动作是为什么？

请问:
我使用NuMaker-IoT-M487 开发板, 测试 SYS_SPDMode_Wakeup 这包sample code 然后在debug模式下执行, 并选择RTC alarm进入power down mode , 接着在UART1视窗看到
如下讯息后, 就没看到有wake up的动作, 我将程式停止后 只看到停在这行程式而已 /* Restore HIRC control register */
SYS->IRCTCTL = u32HIRCTRIMCTL; 请问这code的具体动作是如何以及怎么知道已经唤醒?谢谢!!

CPU @ 192000000 Hz

Power manager Power Manager Status 0x0
+-----------------------------------------------------------------+
| SPD Power-down Mode and Wake-up Sample Code |
| Please Select Power Down Mode and Wake up source. |
+-----------------------------------------------------------------+
|[1] SPD0 GPIO Wake-up pin(PA.0) and using rising edge wake up. |
|[2] SPD0 Wake-up tiMER time-out interval is 1024 OSC10K clocks. |
|[3] SPD0 Wake-up by ACMP0.(band-gap voltage) |
|[4] SPD0 Wake-up by RTC Tick. |
|[5] SPD0 Wake-up by RTC Alarm. |
|[6] SPD0 Wake-up by RTC Tamper0(PF.6), Low level. |
|[7] SPD0 Wake-up by BOD. |
|[8] SPD0 Wake-up by LVR. |
|[a] SPD1 GPIO Wake-up pin(PA.0) and using rising edge wake up. |
| SPD1 Wake-up TIMER time-out interval is 1024 OSC10K clocks. |
|[c] SPD1 Wake-up by ACMP0.(band-gap voltage) |
|[d] SPD1 Wake-up by RTC Tick. |
|[e] SPD1 Wake-up by RTC Alarm. |
|[f] SPD1 Wake-up by RTC Tamper0(PF.6), Low level. |
|[g] SPD1 Wake-up by BOD. |
|[h] SPD1 Wake-up by LVR. |
+-----------------------------------------------------------------+
# Set RTC current date/time: 2020/09/04 10:00:00.
# Set RTC alarm date/time: 2020/09/04 10:00:59.
Enter to SPD0 Power-Down mode......