Hi,
Thank you so much for your interest in our products and for using our community.
There is the S32K3 RTD Training eMIOS presentation (attached).
On the other hand, for GPT frequency of 2Hz (500ms) with eMIOS clock frequency of 120MHz you need 60,000,000 ticks:
1s -> 120MHz (120,000,000 ticks)
2Hz = (1/2)s
->120,000,000 *(1/2) = 60,000,000 ticks
But max ticks are 65,534 (16 bits).
Using Global Prescaler = 256 (in Emios_Mcl_Ip driver) and Gpt Emios Prescaler = 15 (in Emios_Gpt driver):
1s -> 120MHz/256/15 (31,250 ticks)
2Hz = (1/2)s
->31,250 *(1/2) = 15,625 ticks
Please find attached project.
This example implement a General Purpose Timer (GPT) with eMIOS (CH_0), such timer generates an interrupt when it reaches to its defined compare value and its respective notification function toggles the on-board blue LED (PTB8).
S32DS 3.6 + RTD 5.0.0 (S32K31XEVB-Q100)

Hope it helps you.
Have a nice day!