MC9S12HY64 Datasheet, PDF (567/792 Pages) Freescale Semiconductor, Inc – S12 Microcontrollers

48 KByte Flash Module (S12FTMRC48K1V1)
16.3 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.
16.3.1 Module Memory Map
The S12 architecture places the P-Flash memory between global addresses 0x3_4000 and 0x3_FFFF as
shown in Table 16-2.The P-Flash memory map is shown in Figure 16-2.
The FPROT register, described in Section 16.3.2.9, can be set to protect regions in the Flash memory from
Table 16-2. P-Flash Memory Addressing
Global Address
0x3_4000 – 0x3_FFFF
Size
(Bytes)
Description
48 K
P-Flash Block
Contains Flash Configuration Field
(see Table 16-3)
accidental program or erase. Three separate memory regions, one growing upward from global address
0x3_8000 in the Flash memory (called the lower region), one growing downward from global address
0x3_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 16-3.
Table 16-3. Flash Configuration Field
Global Address
0x3_FF00-0x3_FF07
0x3_FF08-0x3_FF0B¹
0x3_FF0C¹
0x3_FF0D¹
0x3_FF0E¹
0x3_FF0F¹
Size
(Bytes)
Description
Backdoor Comparison Key
8
Refer to Section 16.4.5.11, “Verify Backdoor Access Key Command,” and
Section 16.5.1, “Unsecuring the MCU using Backdoor Key Access”
4
Reserved
1
P-Flash Protection byte.
Refer to Section 16.3.2.9, “P-Flash Protection Register (FPROT)”
1
D-Flash Protection byte.
Refer to Section 16.3.2.10, “D-Flash Protection Register (DFPROT)”
1
Flash Nonvolatile byte
Refer to Section 16.3.2.16, “Flash Option Register (FOPT)”
1
Flash Security byte
Refer to Section 16.3.2.2, “Flash Security Register (FSEC)”
MC9S12HY/HA-Family Reference Manual, Rev. 1.04
Freescale Semiconductor
567