参数资料
型号: AT89S4051-24SC
厂商: ATMEL CORP
元件分类: 微控制器/微处理器
英文描述: 8-bit Microcontroller with 2K/4K Bytes Flash
中文描述: 8-BIT, FLASH, 24 MHz, MICROCONTROLLER, PDSO20
封装: 0.300 INCH, MS-013AC, PLASTIC, SOIC-20
文件页数: 8/45页
文件大小: 981K
代理商: AT89S4051-24SC
8
3390C–MICRO–7/05
AT89S2051/S4051
10. Reset
During reset, all I/O Registers are set to their initial values, the port pins are weakly pulled to
V
CC
, and the program starts execution from the Reset Vector, 0000H. The AT89S2051/S4051
has three sources of reset: power-on reset, brown-out reset, and external reset.
10.1
Power-On Reset
A Power-On Reset (POR) is generated by an on-chip detection circuit. The detection level is
nominally 1.4V. The POR is activated whenever V
CC
is below the detection level. The POR cir-
cuit can be used to trigger the start-up reset or to detect a supply voltage failure in devices
without a brown-out detector. The POR circuit ensures that the device is reset from power-on.
When V
CC
reaches the Power-on Reset threshold voltage, the Pierce Oscillator is enabled (if the
XTAL Oscillator Bypass fuse is OFF). Only after V
CC
has also reached the BOD (brown-out
detection) level (see
Section 10.2 ”Brown-out Reset”
), the BOD delay counter starts measuring a
2-ms delay after which the Internal Reset is deasserted and the microcontroller starts executing.
The built-in 2-ms delay allows the V
CC
voltage to reach the minimum 2.7V level before execut-
ing, thus guaranteeing the maximum operating clock frequency. The POR signal is activated
again, without any delay, when V
CC
falls below the POR threshold level. A Power-On Reset (i.e.
a cold reset) will set the POF flag in PCON. Refer to
Figure 10-1
for details on the POR/BOD
behavior.
Figure 10-1.
Power-up and Brown-out Detection Sequence
POR
POR Level 1.4V
BOD Level 2.
3
V
Min V
Level 2.7V
XTAL1
BOD
Intern
a
l
RE
S
ET
t
t
t
t
t
V
CC
t
POR
(2 m
s
)
t
POR
(2 m
s
)
t
POR
(2 m
s
)
2.4V
1.2V
0
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相关代理商/技术参数
参数描述
AT89S4051-24SU 功能描述:8位微控制器 -MCU 4K FLASH 24MHZ RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
AT89S4051-24SUR 功能描述:8051 89S Microcontroller IC 8-Bit 24MHz 4KB (4K x 8) FLASH 20-SOIC 制造商:atmel 系列:89S 包装:管件 零件状态:有效 核心处理器:8051 核心尺寸:8-位 速度:24MHz 连接性:UART/USART 外设:欠压检测/复位,POR,PWM I/O 数:15 程序存储容量:4KB(4K x 8) 程序存储器类型:闪存 EEPROM 容量:- RAM 容量:256 x 8 电压 - 电源(Vcc/Vdd):2.7 V ~ 5.5 V 数据转换器:- 振荡器类型:内部 工作温度:-40°C ~ 85°C(TA) 封装/外壳:20-SOIC(0.295",7.50mm 宽) 供应商器件封装:20-SOIC 标准包装:37
AT89S4D12-12RC 功能描述:8位微控制器 -MCU Microcontroller RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
AT89S4D12-12RI 功能描述:8位微控制器 -MCU Microcontroller RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
AT89S51-24AC 功能描述:8位微控制器 -MCU 4K ISP FLASH 2.7 TO 5.5V - 24 MHZ RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT