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TMP89FM42
RA000
5. Watchdog Timer (WDT)
The watchdog timer is a fail-safe system to detect rapidly the CPU malfunctions such as endless loops due to spu-
rious noises or the deadlock conditions, and return the CPU to a system recovery routine.
The watchdog timer signals used for detecting malfunctions can be programmed as watchdog interrupt request sig-
nals or watchdog timer reset signals.
Note: Care must be taken in system designing since the watchdog timer may not fulfill its functions due to disturbing noise
and other effects.
5.1
Configuration
Figure 5-1 Watchdog Timer Configuration
5.2
Control
The watchdog timer is controlled by the watchdog timer control register (WDCTR), the watchdog timer control
code register (WDCDR), the watchdog timer counter monitor (WDCNT) and the watchdog timer status (WDST).
The watchdog timer is enabled automatically just after the warm-up operation that follows reset is finished.
Watchdog timer control register
WDCTR
(0x0FD4)
7
6
5
4
3
2
1
0
Bit Symbol
-
-
WDTEN
WDTW
WDTT
WDTOUT
Read/Write
R
R
R/W
R/W
R/W
R/W
After reset
1
0
1
0
0
1
1
0
Source clock
Watchdog timer interrupt requestl
CPU/peripheral circuits reset
fcgck/2
10
or fs/2
3
fcgck/2
12
or fs/2
5
fcgck/2
14
or fs/2
7
fcgck/2
16
or fs/2
9
Watchdog timer reset signal
2
8
WDCTR
WDCDR
WDCNT
WDST
Overflow
Clear
2 3 4
6
7 8
5
Control code
decoder
Disable
control circuit
Disable code
(0xB1)
Clear code
(0x4E)
N
E
T
D
W
W
T
D
W
T
T
D
W
T
U
O
T
D
W
T
S
T
D
W
1
T
S
T
NI
W
2
T
S
T
NI
W
Clear time control circuit
8-bit up counter
Interrupt
request/reset
signal control
circuit
r
ot
c
el
e
S
Содержание TLCS-870/C1 Series
Страница 1: ...8 Bit Microcontroller TLCS 870 C1 Series TMP89FM42 查询TMP89FM42供应商 捷多邦 专业PCB打样工厂 24小时加急出货 ...
Страница 3: ...Revision History Date Revision 2007 10 25 1 First Release 2007 11 3 2 Contents Revised ...
Страница 4: ......
Страница 14: ......
Страница 18: ...1 3 Block Diagram TMP89FM42 1 3 Block Diagram Figure 1 2 Block Diagram ...
Страница 22: ...1 4 Pin Names and Functions TMP89FM42 ...
Страница 60: ...2 CPU Core 2 5 Revision History TMP89FM42 ...
Страница 76: ...3 Interrupt Control Circuit 3 8 Revision History TMP89FM42 ...
Страница 86: ...4 External Interrupt control circuit 4 3 Function TMP89FM42 ...
Страница 102: ...7 Voltage Detection Circuit 7 5 Revision History TMP89FM42 ...
Страница 126: ...8 I O Ports 8 3 I O Port Registers TMP89FM42 Note 2 i 0 to 1 ...
Страница 136: ...8 I O Ports 8 5 Revision History TMP89FM42 ...
Страница 142: ...9 Special Function Registers 9 3 SFR3 0x0E40 to 0x0EFF TMP89FM42 ...
Страница 146: ...10 Low Power Consumption Function for Peripherals TMP89FM42 ...
Страница 149: ...TMP89FM42 11 3 Revision History Rev Description RA001 Deleted SLEEP2 description ...
Страница 150: ...11 Divider Output DVO 11 3 Revision History TMP89FM42 ...
Страница 220: ...15 Real Time Clock RTC 15 4 Real Time Clock Operation TMP89FM42 ...
Страница 250: ...16 Asynchronous Serial Interface UART 16 15 Revision History TMP89FM42 ...
Страница 302: ...18 Serial Bus Interface SBI 18 7 Revision History TMP89FM42 ...
Страница 336: ...21 Flash Memory 21 4 Toggle Bit D6 TMP89FM42 Note 1 Make sure that you set the C register to 0x00 LD FLSCR2 0xD5 ...
Страница 338: ...21 Flash Memory 21 4 Toggle Bit D6 TMP89FM42 ...
Страница 384: ...22 Serial PROM Mode 22 15 Revision History TMP89FM42 ...
Страница 388: ...24 Input Output Circuit 24 1 Control Pins TMP89FM42 ...
Страница 404: ...25 Electrical Characteristics 25 11 Revision History TMP89FM42 ...
Страница 406: ...26 Package Dimensions TMP89FM42 ...
Страница 408: ......