Disable HSE

[Jojo_Hu]

Hi,

For S32K312, can HSE be disabled after it has been enabled and the firmware has been downloaded?

[VaneB · Accepted solution]

Hi @Jojo_Hu 

For development purposes, when working in the CUST_DEL life cycle, firmware erase functionality was introduced. This erase functionality is available starting from version 0.2.40.0 and newer, across all S32K3 devices. If you are using an older version like 0.2.6.0, this feature will not be available.

There are two key HSE services:

• HSE_SRV_ID_ERASE_FW – This service erases the HSE firmware, its backup, and the system image (SYS-IMG).
• HSE_SRV_ID_ERASE_HSE_NVM_DATA – This one only erases the SYS-IMG.

It is important to note that even after using HSE_SRV_ID_ERASE_FW, the flash memory originally allocated for the HSE firmware remains reserved for it. That means you will not gain access to that flash space.

Also, if you previously installed an AB SWAP version and then erased it, the OTA flag (which is an OTP) will still be set. Because of this, you should not install a FULL MEM version on such a device afterward.

For a simple guide on how to trigger the HSE_SRV_ID_ERASE_FW service, please refer to the following thread where my colleague explains the process:

HSE firmware installation

BR, VaneB

[Jojo_Hu]

Hi,
If HSE FW and NVM DATA (full data flash region was allocated for NVM DATA) have been erased, can the data flash be used by application?

[Jojo_Hu]

“It is important to note that even after using HSE_SRV_ID_ERASE_FW, the flash memory originally allocated for the HSE firmware remains reserved for it. That means you will not gain access to that flash space.”
The problem I'm facing is, after excuting HSE_SRV_ID_ERASE_FW & HSE_SRV_ID_ERASE_HSE_NVM_DATA (previously the whole data flash was allocated for HSEfirmware) , is there any way for the data flash to be used? ,

[VaneB]

Hi @Jojo_Hu 

As previously mentioned, this memory remains reserved and is exclusively accessible by HSE. Please note that there is no available method to access it from outside the HSE domain.

[Jojo_Hu]

Hi VanB,

Understood. Thanks for your help.