Freescale Semiconductor MPC5604B - Page 325

MPC5604B/C Microcontroller Reference Manual, Rev. 8
314 Freescale Semiconductor
18.5.2.4 MPU Region Descriptor n (MPU_RGDn)
Each 128-bit (16 byte) region descriptor specifies a given memory space and the access attributes
associated with that space. The descriptor definition is the very essence of the operation of the Memory
Protection Unit.
The region descriptors are organized sequentially in the MPU’s programming model and each of the four
32-bit words are detailed in the subsequent sections.
18.5.2.4.1 MPU Region Descriptor n, Word 0 (MPU_RGDn.Word0)
The first word of the MPU region descriptor defines the 0-modulo-32 byte start address of the memory
region. Writes to this word clear the region descriptor’s valid bit (see Section 18.5.2.4.4, “MPU Region
Descriptor n, Word 3 (MPU_RGDn.Word3) for more information).
18.5.2.4.2 MPU Region Descriptor n, Word 1 (MPU_RGDn.Word1)
The second word of the MPU region descriptor defines the 31-modulo-32 byte end address of the memory
region. Writes to this word clear the region descriptor’s valid bit (see Section 18.5.2.4.4, “MPU Region
Descriptor n, Word 3 (MPU_RGDn.Word3) for more information).
Offset: 0x400 + (16*n) + 0x0 (MPU_RGDn.Word0) Access: Read/write
0123456789101112131415
R SRTADDR[26:11]
W
Reset––––––––––––––––
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
R SRTADDR[10:0] 00000
W
Reset–––––––––––00000
Figure 18-5. MPU Region Descriptor, Word 0 Register (MPU_RGDn.Word0)
Table 18-5. MPU_RGDn.Word0 field descriptions
Field Description
SRTADDR Start Address
This field defines the most significant bits of the 0-modulo-32 byte start address of the memory
region.