NXP Semiconductors MPC5566 - Introduction

MPC5566 Microcontroller Reference Manual, Rev. 2
Freescale Semiconductor 5-1
Chapter 5
Peripheral Bridge (PBRIDGE A and PBRIDGE B)
5.1 Introduction
There are two peripheral bridges, PBRIDGE_A and PBRIDGE_B, which act as interfaces between the
system bus and lower bandwidth peripherals. In this manual, PBRIDGE refers to either of these bridges,
as their functionality is identical. The only difference is the peripherals to which they connect. Accesses
that fall within the address space of the PBRIDGE are decoded to provide individual module selects for
peripheral devices on the slave bus interface.
5.1.1 Block Diagram
The PBRIDGE is the interface between the system bus and on-chip peripherals as shown in Figure 5-1.
Figure 5-1. PBRIDGE Interface
5.1.2 Access Protections
The PBRIDGE provides programmable access protections for both masters and peripherals. Access
protections allow the program to:
• Override the privilege level of a master to change it to user mode privilege
• Designate masters as trusted or untrusted
Peripherals can implement the following restrictions:
Off-platform slave
Peripheral
On-platform slave
Peripheral
bridge A
(PBRIDGE_B)(PBRIDGE_A)
bridge B
Off-platform slave
System bus
System bus
System bus crossbar switch (XBAR)
On-platform slave