MAC7200 datasheet(435/976 Pages) FREESCALE

435 / 976 page

MAC7200 Microcontroller Family Reference Manual, Rev. 2

Freescale Semiconductor

357

Chapter 18

FLASH (H7Fb) and FLASH Controller (PFLASH)

This chapter provides an overview of the flash array and the flash controller as they are implemented on

the MAC72xx. Please refer to Chapter 19, “Hip7a Low-Cost Embedded Flash (H7Fb)” for more detailed

technical information on the flash array, and Chapter 20, “SPP Flash Controller (PFLASH_H7Fb)

Module” for more detailed information on the flash controller.

18.1

Introduction

The Flash Module provides the non-volatile memory and its control interface for the MAC7200 family of

devices. Its implementation offers a range of memory sizes depending on the device and intended function

of the memory. For more information on the non-volatile memory options within the MAC7200 family

please refer to Figure 1-1 in Chapter 1, “Introduction”.

The Flash provides two types of memory, the Flash main array and the Shadow Block. The Flash main

array (also sometimes referred to as the Program Flash) is connected directly to the core via the crossbar

switch (See Chapter 16, “AHB to IPI Bridge (AIPS)”). The Shadow Block can be used to store the primary

boot loader. This memory is accessed across the same interface as the Flash main array and is constructed

using the same basic array and memory cell as the Flash main array.

On the MAC72x1 devices 512 K of Flash main array and a 32K Shadow Block are available, on the

MAC72x2 devices, up to 320K of Flash main array and a 32K Shadow Block are available.

The Shadow Block includes several locations which hold information on the state of the Flash main array

and Shadow Block protection, access and security, as well as a security key to unlock the device, if

enabled. The security state of the entire MCU is determined solely by the security settings stored in the

Shadow Block. The device can only be unlocked by writing this security key or by using a JTAG Lockout

Recovery mechanism to erase and very the contents of the non-volatile memory. Please refer to

Section 18.7.9, “Flash Security” for more details.

Both the Flash main array and Shadow Block memories are provided with protection sectors to help

eliminate errors caused by inadvertent program or erase operations being executed on the wrong area of

the memory. The Flash main array has 6 protected sectors, with 2 sectors of 128K and 4 sectors of 16K.

The Shadow Block has a single sector of 32K.

— Flash Main Array (New): 15x4K + 1x196K + 15x4K + 1x196K

— Shadow Block (New): 8x4K

In addition to the erase/program protection provided, both the Flash main array and Shadow Block may

be protected against unintended accesses, based on the access type (read vs. write, supervisor vs. user

mode and instruction fetch vs. data access). The Flash main array has 32 access protection sectors, 30 with

4K and 2 with the remaining 200K. The Shadow Block has 8 access protection sectors, each with 4K, and

may not be protected against writes. This will restrict accesses to the defined sector to be only possible

MAC7200 Datasheet(PDF) 435 Page - Freescale Semiconductor, Inc