The MAX9257/MAX9258 programmable serializer/deserializer (SerDes) devices transfer both video data and control signals over the same twisted-pair cable. However, control data can only be transmitted during the vertical blank time, which is indicated by the control-channel-enabled output (CCEN) signal. The electronic control unit (ECU) firmware designer needs to know how quickly to respond to the CCEN signal before it times out and how to calculate this duration. This application note describes how to calculate the duration of the CCEN for the MAX9257/MAX9258 SerDes chipset. The calculation is based on STO timeout, clock frequency, and UART bit timing. The CCEN duration is programmable and can be closed if not in use.
上传时间： 2014-01-24
上传用户：xingisme
现有基于MAX7219芯片的数码管驱动电路只适用于小尺寸LED，为扩展其使用范围，在介绍动态显示芯片MAX7219功能的基础上，提出了一个基于该芯片的8位高亮度8英寸数码管驱动电路。电路保留了MAX7219芯片的功能强大、编程简单等优点，通过74LS273锁存器和ULN2803达林顿驱动器，实现了对任意大尺寸数码管提供较高电压和电流驱动的静态显示，并亮度可调。 Abstract: The existing display-driving circuit based on MAX7219 was only applicable to small-size LED. To expand its use, based on the function introduction of dynamic display chip MAX7219, a display-driving circuit for high-brightness 8-bit LED with the size of 8-inch was proposed. The advantages of MAX7219 were retained, such as powerful function and simple programming. Static display with adjustable brightness for large-size LED with higher voltage and current was achieved with the help of 74LS273 and ULN2803.
上传时间： 2013-10-23
上传用户：31633073
为解决当前计算机串行通讯接口只有USB，难以满足旧型号设备或某些单片机要求RS232通讯的问题，设计出两款RS232/USB电路。采用CH341A与MAX223集成电路芯片构建标准9线RS232/USB通用接口转换器，无需编程。采用CH341A与PIC16F877A构建单片机与计算机之间的USB通讯电路，软件遵循RS232通讯协议，硬件进行电平转换。实际使用表明，这两款产品与计算机端Windows 操作系统下的串口应用程序完全兼容，且通讯过程中无握手失败现象。 Abstract: To solve the problem that current computer serial communication only with USB interface can not satisfy with the old type equipments or MCU to communicate with RS232， two kinds of RS232/USB circuit were designed.CH341A and MAX223 integrated circuit chips were used to create a standard 9-line RS232/USB universal interface convertor without programme. CH341A and PIC16F877A chips were adopted to build the USB communication circuit between computers and MCU. The software follows RS232 communication protocol， and the hardware converts electrical levels. Actual practices indicate that the two manufactures are compatible with serial application program of Windows operation system completely，and get avoid of handshake lost.
上传时间： 2013-11-03
上传用户：siying
以太网和CAN总线应用广泛，但由于其通信协议不同，两种总线器件间无法进行数据通信，因此，设计了基于CP2200与C8051F040的以太网总线与CAN总线接口转换电路，并给出部分相关硬件电路与软件设计分析。在保证数据完整和协议可靠的前提下，通过握手协议和简化的以太网协议，不仅实现了以太网数据与CAN数据的转发，同时还顺利的解决了以太网的高速性与CAN的低速率冲突，以及两者数据包之间的大小不同的矛盾。 Abstract: In the development of actual application， Ethernet and CAN bus are used very extensively. Owing to its various communication protocols， the communicating between two kinds of bus device can’t be carried out. Therefore， in order to solve this problem， the Ethernet-CAN bus interface circuit based on CP2200 and C8051F040 was designed in this paper， and part of the related hardware circuit and software design analysis were given. On the condition of data’s integrity and protocols’reliability， through the handshaking protocols and the simplified the Ethernet protocol， not only the data switching between CAN and Ethernet was realized， but also the differ in velocity and packet size was solved.
上传时间： 2013-10-15
上传用户：Ants
单片机作为一种微型计算机，其内部具有一定的存储单元（8031除外），但由于其内部存储单元及端口有限，很多情况下难以满足实际需求。为此介绍一种新的扩展方法，将数据线与地址线合并使用，通过软件控制的方法实现数据线与地址线功能的分时转换，数据线不仅用于传送数据信号，还可作为地址线、控制线，用于传送地址信号和控制信号，从而实现单片机与存储器件的有效连接。以单片机片外256KB数据存储空间的扩展为例，通过该扩展方法，仅用10个I/O端口便可实现，与传统的扩展方法相比，可节约8个I/O端口。 Abstract: As a micro-computer,the SCM internal memory has a certain units(except8031),but because of its internal storage units and the ports are limited,in many cases it can not meet the actual demand.So we introduced a new extension method,the data line and address lines combined through software-controlled approach to realize the time-conversion functions of data lines and address lines,so the data lines not only transmited data signals,but also served as address lines and control lines to transmit address signals and control signals,in order to achieve an effective connection of microcontroller and memory chips.Take microcontroller chip with256KB of data storage space expansion as example,through this extension method,with only10I/O ports it was achieved,compared with the traditional extension methods,this method saves8I/O ports.
上传时间： 2014-12-26
上传用户：adada
针对目前汽车追尾事件频发问题，提出一种防汽车车前和车后追尾的安全装置设计。该设计以高性能、低功耗的8位AVR微处理器ATmega8L为核心，结合霍尔式车速传感器、激光雷达测距装置和MMA7260QT加速度传感器，能够兼顾车前和车后，摒弃以往设计中只考虑车前或车后单一性缺点，尤其适用于高速、夜晚或新手行车。 Abstract: Aiming at the high frequency of vehicle rear-end collision，a safe device design of anti-vehicle rear-end collision is presented.In the design，the high-performance，low-power8-bit AVR microprocessor ATmega8L is utilized as a core combined with Hall-type speed sensor，laser-radar ranging devices and the acceleration sensor MMA7260QT.The design considers both the front and back of a car，and overcomes the drawbacks of former designs in which only the front or the back of the car is considered，so it is especially suitable for high-speed，night or the beginner’s driving.
上传时间： 2013-10-14
上传用户：GavinNeko
Mega16是一款采用先进RISC精简指令，内置A/D的8位单片机，可支持低电压联机 Flash和EEPROM 写入功能；同时还支持 Basic和C 等高级语言编程。用它设计电子时钟不仅成本低，硬件简单，而且很容易实现系统移植。介绍了如何利用AVR系列单片机Mega16及1602字符液晶来设计电子时钟的方法，同时给出了相应的电路原理及部分语言程序。 Abstract: ?Mega16 is a high-performance, low power consumption, the use of advanced RISC concise instructions, built-in A/D 8-bit microcontrollers, the on-line support for low-voltage Flash, EEPROM write function. Except Mega16 also support the Basic, C, and other high-level language programming.The electronic clock which is deisgned by Mega16 is not only low-cost, simple hardware, but easy to achieve system migration.The design method of electrioic clock based on the AVR Mega16 and character LCD1602 is introduced in this paper,and the corresponding circuit electrionic and some language program are given.
上传时间： 2014-12-27
上传用户：zl5712176
以AVR单片机ATmega8和USB接口器件PDIUSBD12为核心，基于标准的USB1.1协议，设计一种通用USB接口模块，以满足嵌入式系统中对USB接口的需求。对模块的硬件电路或单片机固件程序的硬件接口层稍加修改即可用于其他各种微处理器。该模块可为各种嵌入式系统增加USB接口,实现与USB主机系统通信。 Abstract: Based on AVR microcontroller ATmega8 and USB interface chip PDIUSBD12, a general USB interface module is designed according to USB1.1 protocol for various requirements of embedded systems. Only with few modifications in circuit or hardware abstract layer of firmware, the module can be used on many types of microprocessors. All kinds of embedded systems can realize high speed and stable communication with USB host systems, owing to the facility of this module.
上传时间： 2014-01-08
上传用户：赵云兴
介绍了电力操作电源与智能电池巡检系统的特点，给出了一种基于超低功耗单片机MSP430 F149针对中小型变电站自动化运行的专用设备的基本设计原理及实现方法，最后给出了详细硬件构成和软件实现。该系统能满足中小型变电站安全、可靠、自动运行的要求，并通过与上位机的串行通信实现变电站的远程管理和控制。 Abstract: The characters of the intelligent battery data logging system of the electric operation power are introduced.The basic design principle and the implemented methods of the special equipment which only designed for the middle or small transformer substation based on MSP430F149 are prescribed. Finally, the hardware block diagram and the software flow chart are also given. The function that the system finally needs to realize can basically meet with the middle or small transformer substation’s satisfy, reliably,and automatic running.And it can also realize the transformer substation long-distance management and control by serial communicating with the host computer.
上传时间： 2013-11-25
上传用户：黄华强
为了在工业生产及过程控制中准确测量温度，设计了一种基于低功耗MSP430单片机的数字温度计。整个系统通过单片机MSP430F1121A控制DS18B20读取温度，采用数码管显示，温度传感器DS18B20与单片机之间通过串口进行数据传输。MSP430系列单片机具有超低功耗，且外围的整合性高，DS18B20只需一个端口即可实现数据通信，连接方便。通过多次实验证明，该系统的测试结果与实际环境温度一致，除了具有接口电路简单、测量精度高、误差小、可靠性高等特点外，其低成本、低功耗的特点使其拥有更广阔的应用前景。 Abstract: In order to obtain accurate measuring temperature in industrial production and process control， a digital thermometer based on MSP430 MCU is designed. The system uses MSP430F1121A MCU to control DS18B20， and gets the temperature data， which is displayed on the LED. The temperature sensor DS18B20 and MCU transmit data through serial communication. MSP430 series has ultra-low power and high integration， DS18B20 only needs one port to achieve data communication. Through many experimental results prove， this system is consistent with actual environment temperature. The system has characteristics of interface circuit simple， high measuring accuracy， minor error， high reliability， besides， the characteristics of low cost and low power make it having vaster application prospect.
上传时间： 2013-10-16
上传用户：wettetw
