Steps to reproduce:
1. On F2837xD, set address 0x5F444 with value 0x67C0 on CPU1
2. On CPU2, try to load a flash program.
3. You will get a bunch of "Error setting the GSxMSEL register for Flash operations" errors

This is because only the 0xF000 bits of the register are checked, but compared to the full value of the cache.