MC9S12KG128_10 Datasheet, PDF (117/606 Pages) Freescale Semiconductor, Inc – HCS12 Microcontrollers

Chapter 3
2 Kbyte EEPROM Module (S12EETS2KV1)
3.1 Introduction
This document describes the EETS2K module which is a 2 Kbyte EEPROM (nonvolatile) memory. The
EETS2K block uses a small sector Flash memory to emulate EEPROM functionality. It is an array of
electrically erasable and programmable, nonvolatile memory. The EEPROM memory is organized as 1024
rows of 2 bytes (1 word). The EEPROM memory’s erase sector size is 2 rows or 2 words (4 bytes).
The EEPROM memory may be read as either bytes, aligned words, or misaligned words. Read access time
is one bus cycle for byte and aligned word, and two bus cycles for misaligned words.
Program and erase functions are controlled by a command driven interface. Both sector erase and mass
erase of the entire EEPROM memory are supported. An erased bit reads 1 and a programmed bit reads 0.
The high voltage required to program and erase is generated internally by on-chip charge pumps.
It is not possible to read from the EEPROM memory while it is being erased or programmed.
The EEPROM memory is ideal for data storage for single-supply applications allowing for field
reprogramming without requiring external programming voltage sources.
CAUTION
An EEPROM word must be in the erased state before being programmed.
Cumulative programming of bits within a word is not allowed.
3.1.1 Glossary
Command Write Sequence — A three-step MCU instruction sequence to program, erase, or erase verify
the EEPROM.
3.1.2 Features
• 2 Kbytes of EEPROM memory
• Minimum erase sector of 4 bytes
• Automated program and erase algorithms
• Interrupts on EEPROM command completion and command buffer empty
• Fast sector erase and word program operation
• 2-stage command pipeline
• Flexible protection scheme for protection against accidental program or erase
• Single power supply program and erase
MC9S12KG128 Data Sheet, Rev. 1.16
Freescale Semiconductor
117