sc9s08mz16 Freescale Semiconductor, Inc, sc9s08mz16 Datasheet - Page 44

• Manufacturer Part Number: sc9s08mz16
• Description: Hcs08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

1
1
0x1852
0x1853
0x1854
0x1855
0x1856
0x1857
0x1858
0x1859
0x185A
0x185B–
0x185F
0xFFB0–
0xFFB7
0xFFB8–
0xFFBC
0xFFBD
0xFFBE
0xFFBF
Chapter 4 Memory
Nonvolatile flash registers, shown in
an 8-byte backdoor key which optionally 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.
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 (SEC01:SEC00) to the unsecured state (1:0).
4.3
The SC9S08MZ16 includes static RAM. The locations in RAM below 0x0100 can be accessed using the
more efficient direct addressing mode, and any single bit in this area can be accessed with the bit
44
Address
Address
This reserved bit must always be written to 0.
This location can be used to store the factory trim value for the ICG.
PTEDS
Reserved
PTFPE
PTFSE
PTFDS
Reserved
PTGPE
PTGSE
PTGDS
Reserved
NVBACKKEY
Reserved
NVPROT
Reserved
NVOPT
RAM
Register Name
Register Name
1
Table 4-3. High-Page Register Summary (Sheet 3 of 3)
PTEDS7
KEYEN
FPS7
Bit 7
Bit 7
—
—
—
—
—
—
—
R
R
R
0
0
0
Table 4-4. Nonvolatile Register Summary
SC9S08MZ16 MCU Data Sheet, Rev. 0 Draft C
FNORED
PTEDS6
PTGPE6
PTGSE6
PTGDS6
Table
FPS6
—
—
—
—
—
—
—
R
R
R
6
6
4-4, are located in the flash memory. These registers include
PTGPE5
PTGSE5
PTGDS5
PTEDS5
PTFDS5
PTFPE5
PTFSE5
FPS5
—
—
—
—
—
—
—
5
5
0
8-Byte Comparison Key
PTEDS4
PTFPE4
PTFSE4
PTFDS4
FPS4
—
—
—
—
—
—
—
4
0
0
0
4
0
PTGPE3
PTGSE3
PTGDS3
PTEDS3
FPS3
—
—
—
—
—
—
—
R
R
R
3
3
0
PTGDS2
PTEDS2
PTGPE2
PTGSE2
FPS2
—
—
—
—
—
—
—
R
R
R
2
2
0
Freescale Semiconductor
PTEDS1
PTGPE1
PTGSE1
PTGDS1
PTFPE1
PTFSE1
PTFDS1
SEC01
FPS1
—
—
—
—
—
—
—
1
1
PTGDS0
PTEDS0
PTFDS0
PTGPE0
PTGSE0
PTFPE0
PTFSE0
SEC00
FPDIS
Bit 0
Bit 0
—
—
—
—
—
—
—