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Chapter 23 1024 KByte Flash Module (S12XFTM1024K5V2)
MC9S12XE-Family Reference Manual , Rev. 1.07
848
Freescale Semiconductor
23.3
Memory Map and Registers
ThissectiondescribesthememorymapandregistersfortheFlashmodule.Readaccesstounimplemented
or reserved memory space in the Flash module will return 0x0000. Write access to unimplemented or
reserved memory space in the Flash module will be ignored by the Flash module.
23.3.1
Module Memory Map
The P-Flash memory map is shown in
Figure 23-2
. The S12X architecture places the P-Flash memory
between global addresses 0x70_0000 and 0x7F_FFFF as shown in
Table 23-2
.
The FPROT register, described in
Section 23.3.2.9
, 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,canbeactivatedforprotection.TheFlashmemoryaddressescoveredbytheseprotectableregions
areshownintheP-Flashmemorymap.Thehigheraddressregionismainlytargetedtoholdthebootloader
codesinceitcoversthevectorspace.Defaultprotectionsettingsaswellassecurityinformationthatallows
the MCU to restrict access to the Flash module are stored in the Flash configuration field as described in
Table 23-3
.
Table 23-3. Flash Configuration Field
1
Table 23-2. P-Flash Memory Addressing
Global Address
Size
(Bytes)
Description
0x7C_0000 – 0x7F_FFFF
256 K
P-Flash Block 0
Contains Flash Configuration Field
(see
Table 23-3
)
0x7A_0000 – 0x7B_FFFF
128 K
P-Flash Block 1N
0x78_0000 – 0x79_FFFF
128 K
P-Flash Block 1S
0x74_0000 – 0x77_FFFF
256 K
P-Flash Block 2
0x70_0000 – 0x73_FFFF
256 K
P-Flash Block 3
Global Address
Size
(Bytes)
Description
0x7F_FF00 – 0x7F_FF07
8
Backdoor Comparison Key
Refer to
Section 23.4.2.3, “Erase Verify P-Flash Section Command
”
0x7F_FF08 – 0x7F_FF0B
2
4
Reserved
P-Flash Protection byte
.
Refer to
Section 23.3.2.9, “P-Flash Protection Register (FPROT)”
0x7F_FF0C
2
1
0x7F_FF0D
2
1
EEE Protection byte
Refer to
Section 23.3.2.10, “EEE Protection Register (EPROT)”
0x7F_FF0E
2
1
Flash Nonvolatile byte
Refer to
Section 23.3.2.14, “Flash Option Register (FOPT)”