SPC5605BK0CLL6R 用户编程技术手册 - NXP（恩智浦）

1 Introduction

Electrically Erasable and Programmable Read Only Memory

(EEPROM) is often used in applications where runtime-

modifiable data needs to be retained after the power has been

removed. Although the Qorivva MPC55xx, MPC56xx, and

MPC57xx family of microcontrollers do not include

EEPROM, the functionality of this memory type can be

emulated with the flash memory that is available. This

document describes the basic principles behind using Qorivva

EEPROM and flash memory are both non-volatile memories,

meaning they retain their data after power has been removed.

They are both composed of an array of memory cells, where

each memory cell holds one or more bits of information. In

some designs, multiple cells combine to form a single bit.

For the NOR flash memory on Qorivva devices, each memory

cell stores one bit of information. In EEPROM and flash

memories where each memory cell holds one bit of

information, the default, erased state of the memory cell reads

NXP Semiconductors

by: David McDaid

Contents

1 Introduction................................................................1

2 EEPROM and Flash Memory

Characteristics............................................................1

3 EEPROM Emulation Using Flash

Memory.....................................................................2

4 Read-While-Write.....................................................9

5 Software Implementation and

Variations.............................................. ..................10