Hello Abdullah,
There are two ways to debug‑protect an S32K3xx MCU:
With HSE: Install the HSE firmware, configure Secure Debug using an Application Debug Key/Password (ADKP), and advance the device lifecycle to enforce debug protection. For further details, please create a support ticket, as the HSE firmware and documentation are available under NDA only.
Without HSE: Program a customer debug password into OTP (UTEST) and then advance the lifecycle to restrict or disable debug access.
The non‑HSE debug protection mechanism is explained in detail here:
https://community.nxp.com/t5/S32K-Knowledge-Base/S32K3-Restrict-the-debug-access-with-a-password-whe...
DTCM1 backdoor access can be used by CM7_0 even if CM7_1 is not used; a simple example is available here:
https://community.nxp.com/t5/S32K-Knowledge-Base/Example-S32K314-DTCM1-Backdoor-RTD201-DS34-v3/ta-p/...
Regards,
Daniel