Справочник Пользователя для Freescale Semiconductor Demonstration Board for Freescale MC9S12XHY256 Microcontroller DEMO9S12XHY256 DEMO9S12XHY256
Модели
DEMO9S12XHY256
Memory Mapping Control (S12XMMCV4)
MC9S12XHY-Family Reference Manual, Rev. 1.04
162
Freescale Semiconductor
3.3.2.1
Mode Register (MODE)
Read: Anytime. Write: Only if a transition is allowed (see
The MODE bits of the MODE register are used to establish the MCU operating mode.
Figure 3-4.
Figure 3-5. Mode Transition Diagram when MCU is Unsecured
Address: 0x000B PRR
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
= Unimplemented or Reserved
Figure 3-3. Mode Register (MODE)
Table 3-3. MODE Field Descriptions
Field
Description
7
MODC
Mode Select Bit — This bit controls the current operating mode during RESET high (inactive). The external
mode pin MODC determines the operating mode during RESET low (active). The state of the pin is latched into
the respective register bit after the RESET signal goes inactive (see
mode pin MODC determines the operating mode during RESET low (active). The state of the pin is latched into
the respective register bit after the RESET signal goes inactive (see
).
Write restrictions exist to disallow transitions between certain modes.
illustrates all allowed mode
changes. Attempting non authorized transitions will not change the MODE bits, but it will block further writes to
these register bits except in special modes.
these register bits except in special modes.
Write accesses to the MODE register are blocked when the device is secured.
Normal
Single-Chip
1
Special
Single-Chip
0
RESET
(SS)
0
RESET
1
(NS)
RESET
Transition done by external pins (MODC)
Transition done by write access to the MODE register
1
State
State
State