Boney:
Is it possible to make some SRAM memory regions write protected (Not Read Protect)
The closest thing you can do to simulate this is to declare certain variables PROGMEM, which will place the data into flash memory, so it will be readable but not writeable during program execution. It won't really be SRAM, but will (mostly) look as if it is to your program (which is the basic idea of PROGMEM).