You probably don’t want to do this because of lower performance (~ 10x) and higher power consumption. That said, this is how you do it:
The MPLAB XC32 C compiler provides an easy to use cache configuration file: “pic32_init_cache.S” If you copy this file into your local project directory it will override the default runtime setup code used to initialize the cache.
Change the “__PIC32_CACHE_MODE” from
“_CACHE_WRITEBACK_WRITEALLOCATE” to “_CACHE_DISABLE”
You can find this file in the following XC32 install directory:
…xc32/vx.xx/pic32-libs/libpic32/stubs
File: pic32_init_cache.S
/* Cache Coherency Attributes */
#define _CACHE_WRITEBACK_WRITEALLOCATE 3
#define _CACHE_WRITETHROUGH_WRITEALLOCATE 1
#define _CACHE_WRITETHROUGH_NOWRITEALLOCATE 0
#define _CACHE_DISABLE 2
/* Set __PIC32_CACHE_MODE to the desired coherency attribute */
//#define __PIC32_CACHE_MODE _CACHE_WRITEBACK_WRITEALLOCATE //default runtime setup policy
#define __PIC32_CACHE_MODE _CACHE_DISABLE
Note: “__PIC32_CACHE_MODE” is used to define the KSEG0 cache coherency algorithm bits (K0<2:0>) found in the PIC32MZ’s “CONFIG” register. Please refer to the device data sheet for details.