RAM Mapping for S32K144

[578895789]

Hi , sir: I am using S32K144 for developing VCU , but now I meet a problem . I need to use S32K144 for online calibration , so I add memory addr m_CAL_RAM and m_CAL_FLASH before fixing linkfile :

.CAL_DATA :
{
 KEEP( *(.CAL_DATA) )
 KEEP( *(.CAL_DATA.*) )
} m_CAL_RAM AT > m_CAL_FLASH , then add C Programming Language as follow:

#ifndef CAL_DATA
#define CAL_DATA __attribute__ ( ( section(".CAL_DATA") ) )
#endif
CAL_DATA  const uint16_t  CtrlMode = 0x75 , accomplishing this work , data in RAM could be mapping FLASH，but the work could affect FLASH erasing and writing , I could not to erase and write FLASH which FLASH looks like write-protecting , however the same operation which I used to SPC5744 which could not appearring.so I want to know specific cause which erasing or writing FLASH for S32K144 fail after RAM remapping without 5744 .

[lukaszadrapa]

Hi,

the main point is that there's no HW support for remapping of RAM over flash on S32K1xx devices.

MPC5xxx devices have either Memory Management Unit (MMU) or overlay feature or there's no support (devices with e200z0 cores like MPC560x). MMU or overlay allow you to do remapping for calibration.

But there's no such feature on S32K144. So, it's not clear to me what you want to achieve. Modifying of linker file will not invoke flash protection. Flash can be protected only by FPROT registers.

Regards,

Lukas