參數(shù)資料
型號: M38037M6H-XXXHP
元件分類: 微控制器/微處理器
英文描述: 8-BIT, MROM, 16.8 MHz, MICROCONTROLLER, PQFP64
封裝: 10 X 10 MM, 0.50 MM PITCH, PLASTIC, LQFP-64
文件頁數(shù): 55/83頁
文件大?。?/td> 1009K
代理商: M38037M6H-XXXHP
59
3803 Group (Spec. H)
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
MITSUBISHI MICROCOMPUTERS
WATCHDOG TIMER
The watchdog timer gives a mean of returning to the reset status
when a program cannot run on a normal loop (for example, be-
cause of a software run-away). The watchdog timer consists of an
8-bit watchdog timer L and an 8-bit watchdog timer H.
Watchdog Timer Initial Value
Watchdog timer L is set to “FF16” and watchdog timer H is set to
“FF16” by writing to the watchdog timer control register (address
001E16) or at a reset. Any write instruction that causes a write sig-
nal can be used, such as the STA, LDM, CLB, etc. Data can only
be written to bits 6 and 7 of the watchdog timer control register.
Regardless of the value written to bits 0 to 5, the above-mentioned
value will be set to each timer.
Watchdog Timer Operations
The watchdog timer stops at reset and a countdown is started by
the writing to the watchdog timer control register. An internal reset
occurs when watchdog timer H underflows. The reset is released
after its release time. After the release, the program is restarted
from the reset vector address. Usually, write to the watchdog timer
control register by software before an underflow of the watchdog
timer H. The watchdog timer does not function if the watchdog
timer control register is not written to at least once.
Fig. 55 Structure of Watchdog timer control register
When bit 6 of the watchdog timer control register is kept at “0”, the
STP instruction is enabled. When that is executed, both the clock
and the watchdog timer stop. Count re-starts at the same time as
the release of stop mode (Note). The watchdog timer does not
stop while a WIT instruction is executed. In addition, the STP in-
struction is disabled by writing “1” to this bit again. When the STP
instruction is executed at this time, it is processed as an undefined
instruction, and an internal reset occurs. Once a “1” is written to
this bit, it cannot be programmed to “0” again.
The following shows the period between the write execution to the
watchdog timer control register and the underflow of watchdog
timer H.
Bit 7 of the watchdog timer control register is “0”:
when XCIN = 32.768 kHz; 32 s
when XIN = 16 MHz; 65.536 ms
Bit 7 of the watchdog timer control register is “1”:
when XCIN = 32.768 kHz; 125 ms
when XIN = 16 MHz; 256
s
Note: The watchdog timer continues to count even while waiting for a stop
release. Therefore, make sure that watchdog timer H does not un-
derflow during this period.
Fig. 54 Block diagram of Watchdog timer
XIN
Data bus
XCIN
“10”
“00”
“01”
Main clock division
ratio selection bits
(Note)
“0”
“1”
1/16
Watchdog timer H count
source selection bit
Reset
circuit
STP instruction disable bit
Watchdog timer H (8)
“FF16” is set when
watchdog timer
control register is
written to.
Internal reset
RESET
Watchdog timer L (8)
Note: Either high-speed, middle-speed or low-speed mode is selected by bits 7 and 6 of the CPU mode register.
STP instruction
“FF16” is set when
watchdog timer
control register is
written to.
Reset release time waiting
b7
Watchdog timer H (for read-out of high-order 6 bit)
STP instruction disable bit
0: STP instruction enabled
1: STP instruction disabled
Watchdog timer H count source selection bit
0: Watchdog timer L underflow
1: f(XIN)/16 or f(XCIN)/16
Watchdog timer control register
(WDTCON : address 001E16)
b0
相關PDF資料
PDF描述
M30622M6P-XXXGP 16-BIT, MROM, 24 MHz, MICROCONTROLLER, PQFP100
M32170F6VWG 32-BIT, FLASH, 40 MHz, RISC MICROCONTROLLER, PBGA255
M37544G2SP 8-BIT, OTPROM, 8 MHz, MICROCONTROLLER, PDIP32
M37906M8C-XXXSP 16-BIT, MROM, 20 MHz, MICROCONTROLLER, PDIP42
M32182F8TFP 32-BIT, FLASH, 80 MHz, RISC MICROCONTROLLER, PQFP144
相關代理商/技術參數(shù)
參數(shù)描述
M38037M8108F 制造商:Panasonic Industrial Company 功能描述:IC
M38037M8H-194HP#U0 制造商:Renesas Electronics Corporation 功能描述:8BIT CISC - Trays
M38039FFHFP#U0 功能描述:IC 740 MCU FLASH 60K 64QFP RoHS:是 類別:集成電路 (IC) >> 嵌入式 - 微控制器, 系列:740/38000 產(chǎn)品培訓模塊:CAN Basics Part-1 CAN Basics Part-2 Electromagnetic Noise Reduction Techniques Part 1 M16C Product Overview Part 1 M16C Product Overview Part 2 標準包裝:1 系列:M16C™ M32C/80/87 核心處理器:M32C/80 芯體尺寸:16/32-位 速度:32MHz 連通性:EBI/EMI,I²C,IEBus,IrDA,SIO,UART/USART 外圍設備:DMA,POR,PWM,WDT 輸入/輸出數(shù):121 程序存儲器容量:384KB(384K x 8) 程序存儲器類型:閃存 EEPROM 大小:- RAM 容量:24K x 8 電壓 - 電源 (Vcc/Vdd):3 V ~ 5.5 V 數(shù)據(jù)轉換器:A/D 34x10b,D/A 2x8b 振蕩器型:內部 工作溫度:-20°C ~ 85°C 封裝/外殼:144-LQFP 包裝:托盤 產(chǎn)品目錄頁面:749 (CN2011-ZH PDF) 配用:R0K330879S001BE-ND - KIT DEV RSK M32C/87
M38039FFHHP 功能描述:MCU 3/5V 56K+4K 64-LQFP RoHS:否 類別:集成電路 (IC) >> 嵌入式 - 微控制器, 系列:740/38000 標準包裝:250 系列:56F8xxx 核心處理器:56800E 芯體尺寸:16-位 速度:60MHz 連通性:CAN,SCI,SPI 外圍設備:POR,PWM,溫度傳感器,WDT 輸入/輸出數(shù):21 程序存儲器容量:40KB(20K x 16) 程序存儲器類型:閃存 EEPROM 大小:- RAM 容量:6K x 16 電壓 - 電源 (Vcc/Vdd):2.25 V ~ 3.6 V 數(shù)據(jù)轉換器:A/D 6x12b 振蕩器型:內部 工作溫度:-40°C ~ 125°C 封裝/外殼:48-LQFP 包裝:托盤 配用:MC56F8323EVME-ND - BOARD EVALUATION MC56F8323
M38039FFH-HP#U 制造商:Renesas Electronics Corporation 功能描述:8BIT 740 CISC 56KB FLASH 16.8MHZ 3.3/5V - Trays