The PCA9519 is a 4-channel level translating I2C-bus/SMBus repeater that enables theprocessor low voltage 2-wire serial bus to interface with standard I2C-bus or SMBus I/O.While retaining all the operating modes and features of the I2C-bus system during thelevel shifts, it also permits extension of the I2C-bus by providing bidirectional buffering forboth the data (SDA) and the clock (SCL) lines, thus enabling the I2C-bus or SMBusmaximum capacitance of 400 pF on the higher voltage side. The SDA and SCL pins areover-voltage tolerant and are high-impedance when the PCA9519 is unpowered.
标签: 4channel transla level 9519
上传时间: 2013-11-19
上传用户:jisiwole
The PCA9544A provides 4 interrupt inputs, one for each channeland one open drain interrupt output. When an interrupt is generated byany device, it will be detected by the PCA9544A and the interruptoutput will be driven LOW. The channel need not be active fordetection of the interrupt. A bit is also set in the control byte.Bits 4 – 7 of the control byte correspond to channels 0 – 3 of thePCA9544A, respectively. Therefore, if an interrupt is generated byany device connected to channel 2, the state of the interrupt inputs isloaded into the control register when a read is accomplished.Likewise, an interrupt on any device connected to channel 0 wouldcause bit 4 of the control register to be set on the read. The mastercan then address the PCA9544A and read the contents of thecontrol byte to determine which channel contains the devicegenerating the interrupt. The master can then reconfigure thePCA9544A to select this channel, and locate the device generatingthe interrupt and clear it. The interrupt clears when the deviceoriginating the interrupt clears.
标签: 4channel multiple 9544A 9544
上传时间: 2014-12-28
上传用户:潜水的三贡
Although Stellaris microcontrollers have generous internal SRAM capabilities, certain applicationsmay have data storage requirements that exceed the 8 KB limit of the Stellaris LM3S8xx seriesdevices. Since microcontrollers do not have an external parallel data-bus, serial memory optionsmust be considered. Until recently, the ubiquitous serial EEPROM/flash device was the only serialmemory solution. The major limitations of EEPROM and flash technology are slow write speed, slowerase times, and limited write/erase endurance.Recently, serial SRAM devices have become available as a solution for high-speed dataapplications. The N256S08xxHDA series of devices, from AMI Semiconductor, offer 32 K x 8 bits oflow-power data storage, a fast Serial Peripheral Interface (SPI) serial bus, and unlimited write cycles.The parts are available in 8-pin SOIC and compact TSSOP packages.
上传时间: 2013-10-14
上传用户:cxl274287265
摘要:本水位监测报警器使用5V低压直流电源(也可以用3节5号电池代替)就可以对5~15厘米的水位进行监测,用LED显示和数码管显示水位,并可以对不再此范围内的水位发出报警。主要采用CD4066、74LS86、74LS32、CD4511芯片,再加上数码管、蜂鸣器、发光二极管、电阻这些器件组成一个简单而灵敏的监测报警电路,操作简单,接通电源即可工作。因为大部分电路采用数字电路,所以本水位监测报警器还具有耗能低、准确性高的特点。关键字:译码电路 报警电路 监测电路 Abstract: The water level alarm monitoring the use of 5 V low-voltage DC power (can also use three batteries replaced on the 5th) will be able to 5 to 15 centimeters of water level monitoring, with LED display and digital display of water level, and this can no longer Within the scope of a water level alarm. Mainly CD4066, 74LS86, 74LS32, CD4511 chips, coupled with digital control, buzzer, light-emitting diode, the resistance of these devices composed of a simple and sensitive monitoring alarm circuits. Because the majority of circuits using digital circuitry, so the water level monitored alarm system also has low energy consumption, high accuracy of the characteristics. Keyword: Decoding circuit alarm circuit monitoring circuit
上传时间: 2013-11-05
上传用户:王庆才
基于PIC单片机的低功耗读卡器硬件设计:本文提出了一个完整的基于串口的智能读卡器子系统设计方案并将其实现。读卡器的设计突出了小型化的要求,全部器件使用贴片封装。为了减小读卡器的体积,设计中还使用了串口窃电的技术,使用串口信号线直接给读卡器供电。为此,读卡器使用了省电的设计,采用了省电的集成电路,并大胆简化了许多传统的设计电路。关键字: 读卡器, 单片机, 串口窃电 Abstract: This paper aims to put forward a complete design of Smart IC card reader based onSerial Port and propose the way of realizing it for the purpose of Network Security. SMD isadopted to make Smart IC reader smaller in this design. To reduce the volume of Smart ICreader, Serial Port powered technology is employed to get power from the signal line of Serial Port. For this reason, low-power consumption components are adopted in the design and some traditional designs are simplified to reduce the power consumption.Keywords: Card Reader; Single-chip Computer; Serial Port Powered IC 卡系统保存了加密算法所需要的工作密钥,供加密算法对网络上传输的数据加密使用,是整个系统网络安全的核心。在IC 卡子系统中,读卡器是一个重要的部分。它起着管理IC卡、在IC 卡和PC或网络计算机间传递数据的重要作用。本文以一片PIC单片机为核心完成了基于RS232 串口的读卡器的硬件设计。
上传时间: 2014-04-14
上传用户:wanghui2438
基于单片机控制的二氧化碳浓度测试计:基于CDM4161二氧化碳气体浓度测试模块以及ATtiny26单片机,提出了一种二氧化碳浓度测试计的设计方案。该方案具有硬件电路简单、成本低、可靠性高、测量准确等优点,具有较高的实用价值。 Abstract: Abstract:A desigh scheme of CO2 concentration meter based on CDM4161carbon dioxide concentration test module and ATtiny26micro-controller is presented in this paper.The design scheme features simple hardware circuit,low-cost,high reli-ability,accurate measurement and it has a high practical value.
上传时间: 2013-11-14
上传用户:zjwangyichao
The C500 microcontroller family usually provides only one on-chip synchronous serialchannel (SSC). If a second SSC is required, an emulation of the missing interface mayhelp to avoid an external hardware solution with additional electronic components.The solution presented in this paper and in the attached source files emulates the mostimportant SSC functions by using optimized SW routines with a performance up to 25KBaud in Slave Mode with half duplex transmission and an overhead less than 60% atSAB C513 with 12 MHz. Due to the implementation in C this performance is not the limitof the chip. A pure implementation in assembler will result in a strong reduction of theCPU load and therefore increase the maximum speed of the interface. In addition,microcontrollers like the SAB C505 will speed up the interface by a factor of two becauseof an optimized architecture compared with the SAB C513.Moreover, this solution lays stress on using as few on-chip hardware resources aspossible. A more excessive consumption of those resources will result in a highermaximum speed of the emulated interface.Due to the restricted performance of an 8 bit microcontroller a pin compatible solution isprovided only; the internal register based programming interface is replaced by a set ofsubroutine calls.The attached source files also contain a test shell, which demonstrates how to exchangeinformation between an on-chip HW-SSC and the emulated SW-SSC via 5 external wiresin different operation modes. It is based on the SAB C513 (Siemens 8 bit microcontroller).A table with load measurements is presented to give an indication for the fraction of CPUperformance required by software for emulating the SSC.
标签: synchronous Emulating serial
上传时间: 2014-01-31
上传用户:z1191176801
The solution presented in this paper and in the attached source files emulates the mostimportant SSC functions by using SW routines implemented in C. The code is focused onthe SAB C513, but will fit to all C500 derivatives.Beyond the low level software drivers a test shell is delivered. This shell allows a quicktest of the software drivers by an emulator or a starter kit demo board.
上传时间: 2013-11-24
上传用户:363186
The Motorola MPC106 PCI bridge/memory controller provides a PowerPCªmicroprocessor common hardware reference platform (CHRPª) compliant bridgebetween the PowerPC microprocessor family and the Peripheral Component Interconnect(PCI) bus. In this document, the term Ô106Õ is used as an abbreviation for the phraseÔMPC106 PCI bridge/memory controllerÕ. This document contains pertinent physicalcharacteristics of the 106. For functional characteristics refer to theMPC106 PCI Bridge/Memory Controller UserÕs Manual.This document contains the following topics:Topic PageSection 1.1, ÒOverviewÓ 2Section 1.2, ÒFeaturesÓ 3Section 1.3, ÒGeneral ParametersÓ 5Section 1.4, ÒElectrical and Thermal CharacteristicsÓ 5Section 1.5, ÒPin AssignmentsÓ 17Section 1.6, ÒPinout Listings 18Section 1.7, ÒPackage DescriptionÓ 22Section 1.8, ÒSystem Design InformationÓ 24Section 1.9, ÒDocument Revision HistoryÓ 29Section 1.10, ÒOrdering InformationÓ 29
上传时间: 2013-11-04
上传用户:as275944189
The P90CL301 is a highly integrated 16/32 bit micro-controller especially suitable for applications requiring lowvoltage and low power consumption. It is fully software compatible with the 68000. Furthermore, it provides bothstandard as well as advanced peripheral functions on-chip.One of these peripheral functions is the I2C bus. This report describes worked-out driver software (written in C) toprogram the P90CL301 I2C interface. It also contains interface software routines offering the user a quick start inwriting a complete I2C system application.
上传时间: 2014-01-06
上传用户:气温达上千万的