PXD20RM Datasheet, PDF (1075/1628 Pages) Freescale Semiconductor, Inc – PXD20 Microcontroller

29.3.2.2 Mode Control Register (ME_MCTL)
Address 0xC3FD_C004
Access: User read, Supervisor read/write, Test read/write
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
R
TARGET_MODE
W
000000000000
Reset 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
R1 0 1 0 0 1 0 1 0 0 0 0 1 1 1 1
W
KEY
Reset 1 0 1 0 0 1 0 1 0 0 0 0 1 1 1 1
Figure 29-3. Mode Control Register (ME_MCTL)
This register is used to trigger software-controlled mode changes. Depending on the modes as enabled by
ME_ME register bits, configurations corresponding to unavailable modes are reserved and access to
ME_<mode>_MC registers must respect this for successful mode requests.
NOTE
Byte and half-word write accesses are not allowed for this register as a
predefined key is required to change its value.
Table 29-5. Mode Control Register (ME_MCTL) Field Descriptions
Field
Description
TARGET_M
ODE
KEY
Target device mode — These bits provide the target device mode to be entered by software
programming. The mechanism to enter into any mode by software requires the write operation twice:
first time with key, and second time with inverted key. These bits are automatically updated by
hardware while entering SAFE on hardware request. Also, while exiting from the HALT and STOP
modes on hardware exit events, these are updated with the appropriate RUN0…3 mode value.
0000 RESET
0001 TEST
0010 SAFE
0011 DRUN
0100 RUN0
0101 RUN1
0110 RUN2
0111 RUN3
1000 HALT
1001 reserved
1010 STOP
1011 reserved
1100 reserved
1101 STANDBY
1110 reserved
1111 RESET (destructive)
Control key — These bits enable write access to this register. Any write access to the register with
a value different from the keys is ignored. Read access will always return inverted key.
KEY:0101101011110000 (0x5AF0)
INVERTED KEY:1010010100001111 (0xA50F)
Freescale Semiconductor
PXD20 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
29-17