mc9s12xd256 Freescale Semiconductor, Inc, mc9s12xd256 Datasheet - Page 1151

• Manufacturer Part Number: mc9s12xd256
• Description: Hcs12x Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

28.3
This section describes the memory map and registers for the Flash module.
28.3.1
The Flash memory map is shown in
addresses between global addresses 0x78_0000 and 0x7F_FFFF. The FPROT register, described in
Section 28.3.2.5, “Flash Protection Register
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 Flash memory map. The higher address region is mainly targeted to hold the boot
loader code since it covers the vector space. The lower address region can be used for EEPROM emulation
in an MCU without an EEPROM module since it can be left unprotected while the remaining addresses
are protected from program or erase. 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
Freescale Semiconductor
0x7F_FF08 – 0x7F_FF0C
0x7F_FF00 – 0x7F_FF07
28-1.
Global Address
0x7F_FF0D
0x7F_FF0E
0x7F_FF0F
Memory Map and Register Definition
Module Memory Map
(Bytes)
Size
8
5
1
1
1
Table 28-1. Flash Configuration Field
MC9S12XDP512 Data Sheet, Rev. 2.17
Figure
Backdoor Comparison Key
Refer to
Reserved
Flash Protection byte
Refer to
Flash Nonvolatile byte
Refer to
Flash Security byte
Refer to
28-2. The HCS12X architecture places the Flash memory
(FPROT)”, can be set to protect regions in the Flash memory
Section 28.6.1, “Unsecuring the MCU using Backdoor Key Access”
Section 28.3.2.5, “Flash Protection Register (FPROT)”
Section 28.3.2.8, “Flash Control Register (FCTL)”
Section 28.3.2.2, “Flash Security Register (FSEC)”
Chapter 28 256 Kbyte Flash Module (S12XFTX256K2V1)
Description
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