MC9S08GT16A Datasheet, PDF (47/300 Pages) Freescale Semiconductor, Inc – Microcontrollers

Memory
Table 4-3. High-Page Register Summary (continued)
Address Register Name
0x1811 DBGCAL
0x1812 DBGCBH
0x1813 DBGCBL
0x1814 DBGFH
0x1815 DBGFL
0x1816 DBGC
0x1817 DBGT
0x1818 DBGS
0x1819–
0x181F
Reserved
0x1820 FCDIV
0x1821 FOPT
0x1822 Reserved
0x1823 FCNFG
0x1824 FPROT
0x1825 FSTAT
0x1826 FCMD
0x1827–
0x182B
Reserved
Bit 7
Bit 7
Bit 15
Bit 7
Bit 15
Bit 7
DBGEN
TRGSEL
AF
—
—
DIVLD
KEYEN
—
0
FPS7
FCBEF
FCMD7
—
—
6
6
14
6
14
6
ARM
BEGIN
BF
—
—
PRDIV8
FNORED
—
0
FPS6
FCCF
FCMD6
—
—
5
4
5
4
13
12
5
4
13
12
5
4
TAG
BRKEN
0
0
ARMF
0
—
—
—
—
DIV5
DIV4
0
0
—
—
KEYACC
0
FPS5
FPVIOL
FCMD5
FPS4
FACCERR
FCMD4
—
—
—
—
3
3
11
3
11
3
RWA
TRG3
CNT3
—
—
DIV3
0
—
0
FPS3
0
FCMD3
—
—
2
2
10
2
10
2
RWAEN
TRG2
CNT2
—
—
DIV2
0
—
0
FPS2
FBLANK
FCMD2
—
—
1
1
9
1
9
1
RWB
TRG1
CNT1
—
—
DIV1
SEC01
—
0
FPS1
0
FCMD1
—
—
Bit 0
Bit 0
Bit 8
Bit 0
Bit 8
Bit 0
RWBEN
TRG0
CNT0
—
—
DIV0
SEC00
—
0
FPDIS
0
FCMD0
—
—
Nonvolatile FLASH registers, shown in Table 4-4, are located in the FLASH memory. These registers
include 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.
Table 4-4. Nonvolatile Register Summary
Address Register Name Bit 7
6
5
4
3
0xFFB0 – NVBACKKEY
0xFFB7
8-Byte Comparison Key
0xFFB8 – Reserved
0xFFBC
—
—
—
—
—
—
—
—
—
—
0xFFBD NVPROT
0xFFBE NVICGTRM¹
FPS7
FPS6
FPS5
FPS4
FPS3
NVTRIM
0xFFBF NVOPT
KEYEN FNORED
0
0
0
1 _{NVICGTRM is the factory trim value. This value must be copied to ICGTRM in user code.}
2
—
—
FPS2
0
1
Bit 0
—
—
FPS1
—
—
FPDIS
SEC01 SEC00
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
MC9S08GT16A/GT8A Data Sheet, Rev. 1
Freescale Semiconductor
47