Chapter 25 256 KByte Flash Module (S12XFTM256K2V1)
MC9S12XE-Family Reference Manual , Rev. 1.19
896
Freescale Semiconductor
25.3
Memory Map and Registers
This section describes the memory map and registers for the Flash module. Read data from unimplemented
memory space in the Flash module is undefined. Write access to unimplemented or reserved memory space
in the Flash module will be ignored by the Flash module.
25.3.1
Module Memory Map
The S12X architecture places the P-Flash memory between global addresses 0x78_0000 and 0x7F_FFFF
as shown in
. The P-Flash memory map is shown in
.
The FPROT register, described in
, can be set to protect regions in the Flash memory from
accidental program or erase. Three separate memory regions, one growing upward from global address
0x7F_8000 in the Flash memory (called the lower region), one growing downward from global address
0x7F_FFFF in the Flash memory (called the higher region), and the remaining addresses in the Flash
memory, can be activated for protection. The Flash memory addresses covered by these protectable regions
are shown in the P-Flash memory map. The higher address region is mainly targeted to hold the boot loader
code since it covers the vector space. Default protection settings as well as security information that allows
the MCU to restrict access to the Flash module are stored in the Flash configuration field as described in
.
Table 25-2. P-Flash Memory Addressing
Global Address
Size
(Bytes)
Description
0x7E_0000 – 0x7F_FFFF
128 K
P-Flash Block 0
Contains Flash Configuration Field
(see
0x7A_0000 – 0x7D_FFFF
256 K
No P-Flash Memory
0x78_0000 – 0x79_FFFF
128 K
P-Flash Block 1
Table 25-3. Flash Configuration Field
(1)
Global Address
Size
(Bytes)
Description
0x7F_FF00 – 0x7F_FF07
8
Backdoor Comparison Key
Refer to
Section 25.4.2.12, “Verify Backdoor Access Key Command
,” and
Section 25.5.1, “Unsecuring the MCU using Backdoor Key Access
0x7F_FF08 –
0x7F_FF0B
(2)
4
Reserved
0x7F_FF0C
1
P-Flash Protection byte
.
Refer to
Section 25.3.2.9, “P-Flash Protection Register (FPROT)”
0x7F_FF0D
1
EEE Protection byte
Refer to
Section 25.3.2.10, “EEE Protection Register (EPROT)”
0x7F_FF0E
1
Flash Nonvolatile byte
Refer to
Section 25.3.2.14, “Flash Option Register (FOPT)”
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:
S12XE
products
in
208
MAPBGA
packages