因為在sleep mode 主振盪會停止，所以只能用 timer 1 外接石英晶體並設定非同步模式就可以利用 Timer1 的中斷叫醒。

The device can wake-up from SLEEP through one of
the following events:
1. External RESET input on MCLR pin.
2. Watchdog Timer Wake-up (if WDT was
enabled).
3. Interrupt from INT pin, RB port change or a
Peripheral Interrupt.
The following peripheral interrupts can wake the device
from SLEEP:
1. PSP read or write.
2. TMR1 interrupt. Timer1 must be operating as
an asynchronous counter.
3. TMR3 interrupt. Timer3 must be operating as
an asynchronous counter.
4. CCP Capture mode interrupt.
5. Special event trigger (Timer1 in Asynchronous
mode using an external clock).
6. MSSP (START/STOP) bit detect interrupt.
7. MSSP transmit or receive in Slave mode
(SPI/I2C).
8. USART RX or TX (Synchronous Slave mode).
9. A/D conversion (when A/D clock source is RC).
10. EEPROM write operation complete.
11. LVD interrupt.

只要利用計時中斷，只要中斷產生
就會系統就會醒來啦

請問一下程式進入sleep的模式下 可否在我設定的時間自動wake up???若有請問大概要怎麼設計