_hw_mpu_rgdn_word2 Union Reference

HW_MPU_RGDn_WORD2 - Region Descriptor n, Word 2 (RW) More...

#include <MK64F12_mpu.h>

Detailed Description

HW_MPU_RGDn_WORD2 - Region Descriptor n, Word 2 (RW)

Reset value: 0x0061F7DFU

The third word of the region descriptor defines the access control rights of the memory region. The access control privileges depend on two broad classifications of bus masters: Bus masters 0-3 have a 5-bit field defining separate privilege rights for user and supervisor mode accesses, as well as the optional inclusion of a process identification field within the definition. Bus masters 4-7 are limited to separate read and write permissions. For the privilege rights of bus masters 0-3, there are three flags associated with this function: Read (r) refers to accessing the referenced memory address using an operand (data) fetch Write (w) refers to updating the referenced memory address using a store (data) instruction Execute (x) refers to reading the referenced memory address using an instruction fetch Writes to RGDn_WORD2 clear the region descriptor's valid bit (RGDn_WORD3[VLD]). If only updating the access controls, write to RGDAACn instead because stores to these locations do not affect the descriptor's valid bit.

Definition at line 597 of file MK64F12_mpu.h.