application can't read bootloader code space

[Simon Third]

Hi all,

I have an interesting problem where I want to read my bootloaders version (based on the DFU), which I have located at 0x3C100, from my application.

I confirmed that my version word (uint32_t) is making its way to code space at the correct address, but when I try to read it from the main application I always get 0xFFFF.

I have the same code working to read the apps version from 0x16100.

It seems to me that the CPU can't read from bootloader space because some sort of memory protection is in force? But I think the CPU should always be able to read valid code space? Is the SD setting something up that is preventing this?

I'm using SD110 7.1 and Keil.

BR Simon

[Susheel Nuguru]

This is definitely not the hardware memory protection because if memory protection is acting on it, it will either return 0 or hardfault. It will not return 0XFFFF. There must be something else in your code, most probably you are reading the wrong memory. How are you reading the memory?