参数资料
型号: AT89LP428-20AU
厂商: Atmel
文件页数: 80/149页
文件大小: 0K
描述: MCU 8051 4K FLASH SPI 32TQFP
产品培训模块: MCU Product Line Introduction
标准包装: 250
系列: 89LP
核心处理器: 8051
芯体尺寸: 8-位
速度: 20MHz
连通性: SPI,UART/USART
外围设备: 欠压检测/复位,POR,PWM,WDT
输入/输出数: 30
程序存储器容量: 4KB(4K x 8)
程序存储器类型: 闪存
EEPROM 大小: 512 x 8
RAM 容量: 768 x 8
电压 - 电源 (Vcc/Vdd): 2.4 V ~ 5.5 V
振荡器型: 内部
工作温度: -40°C ~ 85°C
封装/外壳: 32-TQFP
包装: 托盘
36
3654A–MICRO–8/09
AT89LP428/828
10.1.1
Quasi-bidirectional Output
Port pins in quasi-bidirectional output mode function similar to standard 8051 port pins. A Quasi-
bidirectional port can be used both as an input and output without the need to reconfigure the
port. This is possible because when the port outputs a logic high, it is weakly driven, allowing an
external device to pull the pin low. When the pin is driven low, it is driven strongly and able to
sink a large current. There are three pull-up transistors in the quasi-bidirectional output that
serve different purposes.
One of these pull-ups, called the “very weak” pull-up, is turned on whenever the port latch for the
pin contains a logic “1”. This very weak pull-up sources a very small current that will pull the pin
high if it is left floating.
A second pull-up, called the “weak” pull-up, is turned on when the port latch for the pin contains
a logic “1” and the pin itself is also at a logic “1” level. This pull-up provides the primary source
current for a quasi-bidirectional pin that is outputting a “1”. If this pin is pulled low by an external
device, this weak pull-up turns off, and only the very weak pull-up remains on. In order to pull the
pin low under these conditions, the external device has to sink enough current to overpower the
weak pull-up and pull the port pin below its input threshold voltage.
The third pull-up is referred to as the “strong” pull-up. This pull-up is used to speed up low-to-
high transitions on a quasi-bidirectional port pin when the port latch changes from a logic “0” to a
logic “1”. When this occurs, the strong pull-up turns on for two CPU clocks quickly pulling the
port pin high. The quasi-bidirectional port configuration is shown in Figure 10-1.
Figure 10-1. Quasi-bidirectional Output
Table 10-3.
Port Configuration Registers
Port
Port Data
Port Configuration
1
P1 (90H)
P1M0 (C2H), P1M1 (C3H)
2
P2 (A0H)
P2M0 (C4H), P2M1 (C5H)
3
P3 (B0H)
P3M0 (C6H), P3M1 (C7H)
4
P4 (C0H)
P4M0 (BEH), P4M1 (BFH)
1 Clock Delay
(D Flip-Flop)
Strong
Very
Weak
Port
Pin
VCC
From Port
Register
Input
Data
PWD
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参数描述
AT89LP428-20JU 功能描述:8位微控制器 -MCU SingleCycle 8051 4K ISP Flash 2.4V 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
AT89LP428-20MH 功能描述:8位微控制器 -MCU SingleCycle 8051 4K ISP Flash 2.4V 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
AT89LP428-20PU 功能描述:8位微控制器 -MCU SingleCycle 8051 4K ISP Flash 2.4V 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
AT89LP51-20AU 功能描述:8位微控制器 -MCU Single Cycle 8051 4K ISP FL 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
AT89LP51-20JU 功能描述:8位微控制器 -MCU Single Cycle 8051 4K ISP FL 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