mc9s08en32 Freescale Semiconductor, Inc, mc9s08en32 Datasheet - Page 42

• Manufacturer Part Number: mc9s08en32
• Description: Hcs08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

1
0x1868
0x1869
0x186A
0x186B–
0x186F
0x1870
0x1871
0x1872
0x1873–
0x18FF
0xFFAE
0xFFAF
0xFFB0–
0xFFB7
0xFFBC
0xFFBD
0xFFBE
0xFFBF
Chapter 4 Memory
Nonvolatile Flash registers, shown in
an 8-byte backdoor key, NVBACKKEY, which can be used to gain access to secure memory resources.
During reset events, the contents of NVPROT and NVOPT in the nonvolatile register area of the Flash
memory are transferred into corresponding FPROT and FOPT working registers in the high-page registers
to control security and block protection options.
0xFFB8–
Provided the key enable (KEYEN) bit is 1, the 8-byte comparison key can be used to temporarily
disengage memory security. This key mechanism can be accessed only through user code running in secure
memory. (A security key cannot be entered directly through background debug commands.) This security
key can be disabled completely by programming the KEYEN bit to 0. If the security key is disabled, the
only way to disengage security is by mass erasing the Flash if needed (normally through the background
debug interface) and verifying that Flash is blank. To avoid returning to secure mode after the next reset,
program the security bits (SEC) to the unsecured state (1:0).
42
Address
Address
This bit is reserved. User must write a 1 to this bit. Failing to do so may result in unexpected behavior.
PTFPE
PTFSE
PTFDS
Reserved
PTGPE
PTGSE
PTGDS
Reserved
Reserved for
storage of FTRIM
Res. for storage of
MCGTRM
NVBACKKEY
Reserved
NVPROT
Reserved
NVOPT
Register Name
Register Name
Table 4-3. High-Page Register Summary (Sheet 3 of 3)
PTFDS7
PTFPE7
PTFSE7
KEYEN
Bit 7
Bit 7
—
—
—
—
—
—
—
0
0
0
0
Reserved
Table 4-4. Nonvolatile Register Summary
MC9S08EN32 Series Data Sheet, Rev. 3
FNORED
PTFPE6
PTFSE6
PTFDS6
Table
—
—
—
—
—
—
—
6
0
0
0
6
0
4-4, are located in the Flash memory. These registers include
PTGPE5
PTGSE5
PTGDS5
PTFDS5
PTFPE5
PTFSE5
—
—
—
—
—
—
—
—
5
5
0
8-Byte Comparison Key
PTGDS4
PTGPE4
PTGSE4
PTFPE4
PTFSE4
PTFDS4
—
—
—
—
—
—
—
4
4
0
0
TRIM
PTGPE3
PTGSE3
PTGDS3
PTFPE3
PTFSE3
PTFDS3
—
—
—
—
—
—
—
3
3
0
0
FPS
PTGDS2
PTFDS2
PTGPE2
PTGSE2
PTFPE2
PTFSE2
—
—
—
—
—
—
—
2
2
0
0
Freescale Semiconductor
PTGPE1
PTGSE1
PTGDS1
PTFPE1
PTFSE1
PTFDS1
—
—
—
—
—
—
—
1
1
0
SEC
PTGPE0
PTGSE0
PTGDS0
PTFDS0
PTFPE0
PTFSE0
FTRIM
Bit 0
Bit 0
—
—
—
—
—
—
—