Freescale Semiconductor ColdFire MCF52210 - Manual (Page 291)

MCF52211 ColdFire® Integrated Microcontroller Reference Manual, Rev. 2
Freescale Semiconductor 18-1
Chapter 18
ColdFire Flash Module (CFM)
18.1 Introduction
18.1.1 Overview
The ColdFire Flash Module (CFM) is a non-volatile memory (NVM) module for integration with a CPU.
The CFM provides 128 Kbytes of 32-bit Flash memory serving as electrically erasable and programmable,
non-volatile memory. The flash memory is ideal for program and data storage for single-chip applications,
allowing for field reprogramming without requiring external programming voltage sources.
The common flash bus interface executes read operations to the flash memory using one or two system
bus cycles to access each flash physical block, with access latency depending on the factory setting of the
CLKSEL bits in the CFMCLKSEL register. Flash physical blocks are interleaved between odd and even
addresses to form a flash logical block. Interleaving allows back-to-back read operations to the flash
memory at an effective access rate of one system bus cycle per word after the initial two-cycle access if
the CLKSEL bits are not set for single cycle access.
It is not possible to read from any flash logical block while the same logical block is being erased,
programmed, or verified. Flash logical blocks are divided into multiple logical pages that can be erased
separately. An erased bit reads 1 and a programmed bit reads 0.