MPC5746R OVERLAY is not effective

[liushiquan]

As the picture shows,   address of YC_UTnkT_swtSrcCfg_C is 0x01015c3e,  that is remapping to 0x4003c03e.

Now 0x4003c03e is 0x56, and the mirror flash 0x09015c3e is also 0x56, but the point is not break.

Why?

[davidtosenovjan]

Pay attention to following example code:

https://community.nxp.com/t5/MPC5xxx-Knowledge-Base/Example-MPC5744P-Flash-Overlay-SRAM-S32DS-Power-...

It is the different device but same principle.

Hope it helps

[liushiquan]

the break point is not break

[liushiquan]

Yes, I has followed the code, to remap ram over flash, and I did it. When I write value to ram, the mirrored flash is changed too.
But the code is still executing as no-mirrored flash, not mirrored flash

[davidtosenovjan]

You would have to execute the code from mirrored address range. 

[liushiquan]

but my code and data is not in mirrored address range.

[davidtosenovjan · Accepted solution]

To use calibration feature (i.e. overlay) you have to execute code or read data from mirrored address range, otherwise calibration is not applied. You can change linker command file configuration if you need to use it so.

[liushiquan]

Will it make the mcu runninig a bit slower, Or is there any other impact?

[davidtosenovjan]

No, it should not run slower: