Recovery mode for S32K328

MorcinM — Mon, 24 Mar 2025 14:54:18 GMT

I am new in S32K3x programming. My question are:

1. Why this so called Recovery Mode is needed in therms of device programming/flashing? Isn't MCU always accessible using debugger or this can be restricted for production firmware and recovery mode is the only way to flash new firmware/reprogram in that case?

2. For the device/MCU already in recovery mode: can be in that case the s32k328 programmed using JTAG or it supports also flashing via UART (meaning: NXP build in support for UART programming)?

Thanks in advance for your support.

Regards,

Marcin

Re: Recovery mode for S32K328

VaneB — Tue, 25 Mar 2025 16:18:41 GMT

Hi @MorcinM

The recovery mode allows the host to recover from abnormal situations. There are two recovery modes: Secure Recovery Mode and JTAG-Based Recovery Mode.

Secure Recovery Mode:

In this mode, the HSE subsystem boots the Secure Recovery Application after its authenticity is confirmed against ADKP.
This mode must be enabled using the HSE_SECURE_RECOVERY_CONFIG_ATTR_ID attribute. The start address and size of the secure recovery application must be provided in the IVT (Image Vector Table).
When this mode is activated, the application core is released at the start address of the Secure Recovery Application.
If Secure Recovery Mode fails, the device will automatically enter JTAG-Based Recovery Mode.

JTAG-Based Recovery Mode:

In this mode, the HSE subsystem waits for a debugger connection (which must be authenticated when the LC is in OEM_PROD or IN_FIELD).
Once the debugger is connected, the HSE releases the device from reset at a predefined address, JTAG_RECOVERY_START_ADDRESS, to a RAM-based application with the application core in sleep mode.

For more detailed information on these modes, refer to section 2.6.1.3 (Recovery Mode) of the HSE_B Firmware Reference Manual, Rev. 2.4.

BR, VaneB

topic Re: Recovery mode for S32K328 in S32K

Recovery mode for S32K328

Re: Recovery mode for S32K328