Please help me. Inquiries about flash memory from MPC5746C

[kimdukyu]

We have two applications. The first application is at 0x1000000 in flash memory, the second application is at 0x01140000. The boot header(0x00FA0000) is the same.

I want to be able to choose a flash memory address during the application call process. I would like to know if it is possible to utilize the flash overlay function for this. As seen in the MPC5746C Reference Manual "Support is also provided to reroute flash access to a different on-chip flash memory address." and like writing. I would like to know how I can reroute to the 0x01140000 flash memory address.

Or I would like to know if there is a way to select the application start address(0x1000000 or 0x1140000).

If you have an example program or document for the above method, please reply.

Thank you.

[davidtosenovjan]

Why you would like to use such unusual method?

Usually bootloader are running always and it decides whether it calls user application or not (or which application if more is flashed). The decision can be made on the basis of state of GPIO pin, content of flash memory, command received via a communication interface or other condition which is required by application.

[kimdukyu]

You said the bootloader was always running, but I'm not sure what that means. How do I enter the bootloader? I don't understand how the bootloader decides whether to call the application or not. Please let me know if you have example programs or documentation.

Thank you

[davidtosenovjan · Accepted solution]

I mean that after power-on-reset bootloader is started up and this bootloader calls application or perform other actions.,

An appnote exists:

https://www.nxp.com/docs/en/application-note/AN5319.pdf

https://www.nxp.com/docs/en/application-note-software/AN5319SW.zip