RTOS: What should be the cache-able option for shared memory for IPC

Tool/software:TI-RTOS

Hi there, I have installed IPC 3.46.00.02 and have run the ex02_messageq example on OMAPL138 and with Linux on ARM.

I don't understand the cache option added in the DSP.cfg file :

var Cache = xdc.useModule('ti.sysbios.family.c64p.Cache');
/* Set 0xc4000000 -> 0xc4ffffff to be non-cached for shared memory IPC */
Cache.MAR192_223 = 0x00000010;

I guess, the comment is wrong to start with. Here we are disabling the 0xc3000000 rather than 0xc4000000. 

Could you explain what is the idea about this cache option? should IPC memory not be cache-able ? 

Attached the full dsp.cfg file for your reference.

Thanks.(Please visit the site to view this file)