參數(shù)資料
型號(hào): AT89LP4052-16SU
廠商: Atmel
文件頁數(shù): 47/94頁
文件大?。?/td> 0K
描述: IC 8051 MCU FLASH 4K 20SOIC
標(biāo)準(zhǔn)包裝: 38
系列: 89LP
核心處理器: 8051
芯體尺寸: 8-位
速度: 16MHz
連通性: SPI,UART/USART
外圍設(shè)備: 欠壓檢測(cè)/復(fù)位,POR,PWM,WDT
輸入/輸出數(shù): 15
程序存儲(chǔ)器容量: 4KB(4K x 8)
程序存儲(chǔ)器類型: 閃存
RAM 容量: 256 x 8
電壓 - 電源 (Vcc/Vdd): 2.4 V ~ 5.5 V
振蕩器型: 內(nèi)部
工作溫度: -40°C ~ 85°C
封裝/外殼: 20-SOIC(0.295",7.50mm 寬)
包裝: 管件
51
3547J–MICRO–10/09
AT89LP2052/LP4052
21. Programmable Watchdog Timer
The programmable Watchdog Timer (WDT) protects the system from incorrect execution by trig-
gering a system reset when it times out after the software has failed to feed the timer prior to the
timer overflow. The WDT counts CPU clock cycles. The prescaler bits, PS0, PS1 and PS2 in
SFR WDTCON are used to set the period of the Watchdog Timer from 16K to 2048K clock
cycles. The WDT is disabled by Reset and during Power-down mode. When the WDT times out
without being serviced, an internal RST pulse is generated to reset the CPU. See Table 21-1 for
the available WDT period selections.
Note:
*The WDT time-out period is dependent on the system clock frequency.
The Watchdog Timer consists of a 14-bit timer with 7-bit programmable prescaler. Writing the
sequence 1EH/E1H to the WDTRST register enables the timer. When the WDT is enabled, the
WDTEN bit in WDTCON will be set to “1”. To prevent the WDT from generating a reset when if
overflows, the watchdog feed sequence must be written to WDTRST before the end of the time-
out period. To feed the watchdog, two write instructions must be sequentially executed success-
fully. Between the two write instructions, SFR reads are allowed, but writes are not allowed. The
instructions should move 1EH to the WDTRST register and then 1EH to the WDTRST register.
An incorrect feed or enable sequence will cause an immediate watchdog reset. The program
sequence to feed or enable the watchdog timer is as follows:
MOV WDTRST, #01Eh
MOV WDTRST, #0E1h
Table 21-1.
Watchdog Timer Time-out Period Selection
WDT Prescaler Bits
Period*
(Clock Cycles)
PS2
PS1
PS0
000
16K
001
32K
010
64K
011
128K
100
256K
101
512K
1
0
1024K
1
2048K
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AT89LP4052-16XI 功能描述:8位微控制器 -MCU Microcontroller RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時(shí)鐘頻率:50 MHz 程序存儲(chǔ)器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
AT89LP4052-16XU 功能描述:8位微控制器 -MCU Microcontroller RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時(shí)鐘頻率:50 MHz 程序存儲(chǔ)器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
AT89LP4052-20PU 功能描述:8位微控制器 -MCU SINGLE CYCLE 4K FLASH-20MHZ 2.4-5.5V RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時(shí)鐘頻率:50 MHz 程序存儲(chǔ)器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
AT89LP4052-20SU 功能描述:8位微控制器 -MCU SINGLE CYCLE 4K FLASH-20MHZ 2.4-5.5V RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時(shí)鐘頻率:50 MHz 程序存儲(chǔ)器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
AT89LP4052-20XU 功能描述:8位微控制器 -MCU SINGLE CYC 4K FLASH -20MHZ 2.4-5.5V RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時(shí)鐘頻率:50 MHz 程序存儲(chǔ)器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT