Freescale Semiconductor MPC5604B - Introduction

MPC5604B/C Microcontroller Reference Manual, Rev. 8
Freescale Semiconductor 741
Chapter 29
Register Protection
29.1 Introduction
The Register Protection module offers a mechanism to protect defined memory-mapped address locations
in a module under protection from being written. The address locations that can be protected are
module-specific.
The protection module is located between the module under protection and the peripheral bridge. This is
shown in Figure 29-1.
Figure 29-1. Register Protection block diagram
Please see the “Registers Under Protection” appendix for the list of protected registers.
29.2 Features
The Register Protection includes these distinctive features:
• Restrict write accesses for the module under protection to supervisor mode only
• Lock registers for first 6 KB of memory-mapped address space
• Address mirror automatically sets corresponding lock bit
• Once configured lock bits can be protected from changes
PBRIDGE
supervisor access /
Lock
Registers
Module
under
Protection
Protection Module
write data
address / access size
UAA
HLB
GCR
Access allowed?
peripheral enable
Other control signals
peripheral
enable