Freescale Semiconductor MC9S12ZVHL32, Reference Manual

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Chapter 3 Memory Mapping Control (S12ZMMCV1)
S12ZVHY/S12ZVHL Family Reference Manual Rev. 1.05
Freescale Semiconductor 119
3.3.2.1 Mode Register (MODE)
Read: Anytime.
Write: Only if a transition is allowed (see Figure 3-4 ).
The MODE register determines the operating mode of the MCU.
CAUTION
Figure 3-4. Mode Transition Diagram
Address: 0x0070
7 6 5 4 3 2 1 0
R
MODC
0 0 0 0 0 0 0
W
Reset MODC
1
0 0 0 0 0 0 0
1. External signal (see Table 3-3 ).
= Unimplemented or Reserved
Figure 3-3. Mode Register (MODE)
Table 3-4. MODE Field Descriptions
Field Description
7
MODC
Mode Select Bit — This bit determines the current operating mode of the MCU. Its reset value is captured from
the MODC pin at the rising edge of the RESET pin.
Figure 3-4
illustrates the only valid mode transition from
special single-chip mode to normal single chip mode.
Reset with
MODC pin = 1
Reset with
MODC pin = 0
Special
Single-Chip
Mode (SS)
Normal
Single-Chip
Mode (NS) write access to
MODE:
1

MODC bit