MC3S12RG128 Datasheet, PDF (439/546 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 15 Read-Only Memory 64K x 16 (ROM64KX16V1) Block Description
15.3.2.2 ROM Configuration Register (RCNFG)
Module Base + 0x0003
7
6
5
4
3
2
1
0
R
0
0
0
0
0
0
0
KEYACC
W
Reset
0
0
0
0
0
0
0
0
Figure 15-4. ROM Configuration Register (RCNFG)
Read: Anytime
Write: Anytime
Table 15-5. RCNFG Field Descriptions
Field
5
KEYACC
Description
Key Access Bit — Enable writing of security access (backdoor) key. This bit enables writing of the backdoor
comparison key for disabling security. This bit cannot be set unless the KEYEN[1:0] bits in the ROPT register are
set to “10”. While this bit is set, normal accesses to the ROM array are blocked, returned data is undefined.
0 Backdoor key access enabled
1 Backdoor key access disabled
15.3.2.3 ROM Device SC Number Registers (RDSC0−RDSC2)
Module Base + 0x000C
Module Base + 0x000D
Module Base + 0x000E
7
6
5
4
3
2
1
0
R
DSCn[7:0]
W
Reset
R¹
R¹
R¹
R¹
R¹
R¹
R¹
R¹
1 _{Read from non-volatile registers in ROM}
Figure 15-5. ROM Device SC Number Register (RDSC0−RDSC2)
Read: Anytime
Write: Never
Table 15-6. RDSC0−RDSC2 Field Descriptions
Field
Description
7−0
Device SC Number n — Device SC Number byte n (n=<0,1,2>).
DSCn[7:0]
MC3S12RG128 Data Sheet, Rev. 1.05
Freescale Semiconductor
439