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ColdFire Flash Module (CFM)
MCF52235 ColdFire® Integrated Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor
17-3
•
Protection scheme to prevent accidental program or erase of flash memory
•
Access restriction control for supervisor/user and data/instruction operations
•
Security feature to prevent unauthorized access to the flash memory
17.2
External Signal Description
The CFM contains no signals that connect off-chip for the end customer.
17.3
Memory Map and Register Definition
This section describes the CFM memory map and registers.
17.3.1
Memory Map
The memory map for the CFM flash memory is shown in
. The starting address of the flash
memory is determined by the flash array base address as defined by the system level configuration. The
flash memory map shows how a pair of 32-bit flash physical blocks (even and odd) interleave every 4 bytes
to form a contiguous memory space as follows:
Flash Block 0 includes byte addresses (PROGRAM_ARR0x0000_0000) to
(PROGRAM_ARR0x0003_FFFF).
Figure 17-2. CFM Flash Memory Map
The CFM has hardware interlocks that protect data from accidental corruption using program or erase
operations. A flexible scheme allows the protection of any combination of flash logical sectors as
described in
Section 17.3.3.4, “CFMPROT — CFM Protection Register
.” A similar scheme is available to
control supervisor/user and data/instruction access to these flash logical sectors.
Security information that allows the MCU to prevent intrusive access to the flash memory is stored in the
flash configuration field. The flash configuration field is composed of 24 bytes of reserved memory space
within the flash memory, which contains information that determines the CFM protection and access
restriction scheme out of reset. A description of each byte found in the flash configuration field is given in
.
(PROGRAM_ARRA 0x0000_0000)
256 Kbytes
•
•
•
Configuration Field
(PROGRAM_ARR0x0400) to
(PROGRAM_ARR0x0417)
BLOCK EVEN (4 bytes)
BLOCK ODD (4 bytes)
BLOCK EVEN (4 bytes)
BLOCK ODD (4 bytes)
(PROGRAM_ARRA 0x0003_FFFF)
Because
of
an
order
from
the
United
States
International
Trade
Commission,
BGA-packaged
product
lines
and
part
numbers
indicated
here
currently
are
not
available
from
Freescale
for
import
or
sale
in
the
United
States
prior
to
September
2010:MCF52234CVM60,
MCF52235CVM60