S912XHZ512F1VAG Datasheet, PDF (858/978 Pages) Freescale Semiconductor, Inc – Covers MC9S12XHZ384, MC9S12XHZ256

Chapter 25 Memory Mapping Control (S12XMMCV3)
RESET
010
Special
Test
(ST)
010
100
101
Normal
100
RESET
Single-Chip
101
110
(NS)
111
100
Normal
Expanded
(NX)
101
101
RESET
001
RESET
Emulation
Single-Chip
(ES)
001
101
001
011
Special
Single-Chip
(SS)
000
000
RESET
Emulation
Expanded
(EX)
011
011
RESET
Transition done by external pins (MODC, MODB, MODA)
RESET
Transition done by write access to the MODE register
110
Illegal (MODC, MODB, MODA) pin values.
111
Do not use. (Reserved for future use).
Figure 25-5. Mode Transition Diagram when MCU is Unsecured
MC9S12XHZ512 Data Sheet, Rev. 1.06
858
Freescale Semiconductor