MC9S12HZ256 Datasheet, PDF (664/692 Pages) Freescale Semiconductor, Inc – HCS12 Microcontrollers

Appendix E ROM Description
E.1.3 Device SC Number Registers
This register contains a copy of the Device SC number which is stored in the non-volatile registers at
addresses 0xFF0C, 0xFF0D and 0xFF0E.
7
6
5
4
3
2
1
0
R
DSCn
W
Reset
R
R
R
R
R
R
R
R
= Unimplemented or Reserved
Figure E-3. Device SC Number (DSCn)
Table E-4. DSCn Field Descriptions
Field
7:0
DSCn
Description
Device SC Number byte n (n= 0,1 or 2) — Reads Device SC number
E.1.4 Non-volatile Registers
A range of addresses in the ROM is reserved for the security bits and backdoor key. In addition, some
locations are reserved for the ROM device SC number and for the 32 bit CRC value used by the BIST
control.
Table E-5. Non-volatile Register Summary
Address Register Name 7
0xFF00 –
0xFF07
NVBACKKEY
0xFF08 NVCRC0
0xFF09 NVCRC1
0xFF0A NVCRC2
0xFF0B NVCRC3
0xFF0C NVSC0
0xFF0D NVSC1
0xFF0E NVSC2
0xFF0F NVOPT
KEYEN1
6
KEYEN0
5
4
3
2
8-Byte Comparison Key
CRC value byte0
CRC value byte1
CRC value byte2
CRC value byte3
Device SC number byte0
Device SC number byte1
Device SC number byte2
NV5
NV4
NV3
NV2
1
0
SEC1 SEC0
NOTE
Please note that backdoor keywords 0x0000 or 0xFFFF are invalid and will
effectively disable backdoor key access when used.
MC9S12HZ256 Data Sheet, Rev. 2.04
664
Freescale Semiconductor