Freescale Semiconductor MPC5553 - Introduction

MPC5553/MPC5554 Microcontroller Reference Manual, Rev. 5
Freescale Semiconductor 16-1
Chapter 16
Boot Assist Module (BAM)
16.1 Introduction
This chapter describes the boot assist module (BAM).
16.1.1 Block Diagram
Figure 16-1 is a block diagram of the BAM.
Figure 16-1. BAM Block Diagram
16.1.2 Overview
The MPC5553/MPC5554 BAM contains the MCU boot program code. The BAM control block is
connected to peripheral bridge B and occupies the last 16 KB of the MCU memory space. The BAM
program supports four different booting modes: from internal flash, from external memory without bus
arbitration, from external memory with bus arbitration, serial boot via SCI or CAN interfaces. The BAM
program is executed by the e200z6 core just after the MCU reset. Depending on the boot mode, the
program initializes appropriate minimum MCU resources to start user code execution.
16.1.3 Features
The BAM program provides:
• Initial e200z6 core MMU setup with minimum address translation for all internal MCU resources
and external memory address space
• Location and detection of user boot code
• Automatic switch to serial boot mode if internal or external flash is blank or invalid
• User programmable 64-bit password protection for serial boot mode
• Booting user code from internal flash module, from external memory without arbitration and from
external memory with arbitration
Peripheral
Bridge B
BAM
Control
Block
BAM