Hello @DanIton92,
Could you please take a look at the LPC540xx/LPC54S0xx User manual. Chapter 9: LPC540xx/LPC54S0xx Power management. Section 9.2 General description?
Table 228 and 229 could be useful to understand how you could use the wake-up sources including the Watchodg/RTC/Micro-tick timers.
Also, it could be useful to take a look to the utick_wakeup examples in the LPC54016 SDK.
Warm regards, Raul.