MC3S12RG128 Datasheet, PDF (435/546 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 15
Read-Only Memory 64K x 16 (ROM64KX16V1)
Block Description
15.1 Introduction
This document describes the ROM64KX16 module which controls a 128 K byte mask-programmed
read-only memory array for use with 0.25 micron HCS12 devices.
15.1.1 Glossary
The following terms and abbreviations are used in the document.
Table 15-1. Terminology
Term
ROM
Read-Only Memory
Meaning
15.1.2 Features
The ROM64KX16 includes the following features:
• Control read access to 128 K bytes of mask-programmed ROM memory comprised of one 64Kx16
byte block
• Security with user backdoor key entry
15.1.3 Modes of Operation
The modes of operation for ROM64KX16 are listed below.
• Run
The ROM64KX16 interface provides one cycle read access to the ROM hard block.
• Standby
Whenever the on-chip ROM is not being accessed, the ROM64KX16 module holds the ROM hard
block in standby.
MC3S12RG128 Data Sheet, Rev. 1.05
Freescale Semiconductor
435