-
The PCA9549 provides eight bits of high speed TTL-compatible bus switching controlledby the I2C-bus. The low ON-state resistance of the switch allows connections to be madewith minimal propagation delay. Any individual A to B channel or combination of channelscan be selected via the I2C-bus, determined by the contents of the programmable Controlregister. When the I2C-bus bit is HIGH (logic 1), the switch is on and data can flow fromPort A to Port B, or vice versa. When the I2C-bus bit is LOW (logic 0), the switch is open,creating a high-impedance state between the two ports, which stops the data flow.An active LOW reset input (RESET) allows the PCA9549 to recover from a situationwhere the I2C-bus is stuck in a LOW state. Pulling the RESET pin LOW resets the I2C-busstate machine and causes all the bits to be open, as does the internal power-on resetfunction.
標(biāo)簽：
switch
Octal
9549
with
上傳時(shí)間：
2014-11-22
上傳用戶：xcy122677
-
The PCA9548A is an octal bidirectional translating switch controlled via the I2C-bus. TheSCL/SDA upstream pair fans out to eight downstream pairs, or channels. Any individualSCx/SDx channel or combination of channels can be selected, determined by thecontents of the programmable control register.An active LOW reset input allows the PCA9548A to recover from a situation where one ofthe downstream I2C-buses is stuck in a LOW state. Pulling the RESET pin LOW resets theI2C-bus state machine and causes all the channels to be deselected as does the internalPower-on reset function.
標(biāo)簽：
channel
9548A
9548
PCA
上傳時(shí)間：
2013-10-13
上傳用戶：bakdesec
-
The PCA9557 is a silicon CMOS circuit which provides parallel input/output expansion for
SMBus and I2C-bus applications. The PCA9557 consists of an 8-bit input port register,
8-bit output port register, and an I2C-bus/SMBus interface. It has low current consumption
and a high-impedance open-drain output pin, IO0.
The system master can enable the PCA9557’s I/O as either input or output by writing to
the configuration register. The system master can also invert the PCA9557 inputs by
writing to the active HIGH polarity inversion register. Finally, the system master can reset
the PCA9557 in the event of a time-out by asserting a LOW in the reset input.
The power-on reset puts the registers in their default state and initializes the
I2C-bus/SMBus state machine. The RESET pin causes the same reset/initialization to
occur without de-powering the part.
標(biāo)簽：
C-bus
SMBus
reset
port
上傳時(shí)間：
2014-01-18
上傳用戶：bs2005
-
All inputs of the C16x family have Schmitt-Trigger input characteristics. These Schmitt-Triggers are intended to always provide proper internal low and high levels, even if anundefined voltage level (between TTL-VIL and TTL-VIH) is externally applied to the pin.The hysteresis of these inputs, however, is very small, and can not be properly used in anapplication to suppress signal noise, and to shape slow rising/falling input transitions.Thus, it must be taken care that rising/falling input signals pass the undefined area of theTTL-specification between VIL and VIH with a sufficient rise/fall time, as generally usualand specified for TTL components (e.g. 74LS series: gates 1V/us, clock inputs 20V/us).The effect of the implemented Schmitt-Trigger is that even if the input signal remains inthe undefined area, well defined low/high levels are generated internally. Note that allinput signals are evaluated at specific sample points (depending on the input and theperipheral function connected to it), at that signal transitions are detected if twoconsecutive samples show different levels. Thus, only the current level of an input signalat these sample points is relevant, that means, the necessary rise/fall times of the inputsignal is only dependant on the sample rate, that is the distance in time between twoconsecutive evaluation time points. If an input signal, for instance, is sampled throughsoftware every 10us, it is irrelevant, which input level would be seen between thesamples. Thus, it would be allowable for the signal to take 10us to pass through theundefined area. Due to the sample rate of 10us, it is assured that only one sample canoccur while the signal is within the undefined area, and no incorrect transition will bedetected. For inputs which are connected to a peripheral function, e.g. capture inputs, thesample rate is determined by the clock cycle of the peripheral unit. In the case of theCAPCOM unit this means a sample rate of 400ns @ 20MHz CPU clock. This requiresinput signals to pass through the undefined area within these 400ns in order to avoidmultiple capture events.For input signals, which do not provide the required rise/fall times, external circuitry mustbe used to shape the signal transitions.In the attached diagram, the effect of the sample rate is shown. The numbers 1 to 5 in thediagram represent possible sample points. Waveform a) shows the result if the inputsignal transition time through the undefined TTL-level area is less than the time distancebetween the sample points (sampling at 1, 2, 3, and 4). Waveform b) can be the result ifthe sampling is performed more than once within the undefined area (sampling at 1, 2, 5,3, and 4).Sample points:1. Evaluation of the signal clearly results in a low level2. Either a low or a high level can be sampled here. If low is sampled, no transition willbe detected. If the sample results in a high level, a transition is detected, and anappropriate action (e.g. capture) might take place.3. Evaluation here clearly results in a high level. If the previous sample 2) had alreadydetected a high, there is no change. If the previous sample 2) showed a low, atransition from low to high is detected now.
標(biāo)簽：
Signal
Input
Fall
Rise
上傳時(shí)間：
2013-10-23
上傳用戶：copu
-
All inputs of the C16x family have Schmitt-Trigger input characteristics. These Schmitt-Triggers are intended to always provide proper internal low and high levels, even if anundefined voltage level (between TTL-VIL and TTL-VIH) is externally applied to the pin.The hysteresis of these inputs, however, is very small, and can not be properly used in anapplication to suppress signal noise, and to shape slow rising/falling input transitions.Thus, it must be taken care that rising/falling input signals pass the undefined area of theTTL-specification between VIL and VIH with a sufficient rise/fall time, as generally usualand specified for TTL components (e.g. 74LS series: gates 1V/us, clock inputs 20V/us).The effect of the implemented Schmitt-Trigger is that even if the input signal remains inthe undefined area, well defined low/high levels are generated internally. Note that allinput signals are evaluated at specific sample points (depending on the input and theperipheral function connected to it), at that signal transitions are detected if twoconsecutive samples show different levels. Thus, only the current level of an input signalat these sample points is relevant, that means, the necessary rise/fall times of the inputsignal is only dependant on the sample rate, that is the distance in time between twoconsecutive evaluation time points. If an input signal, for instance, is sampled throughsoftware every 10us, it is irrelevant, which input level would be seen between thesamples. Thus, it would be allowable for the signal to take 10us to pass through theundefined area. Due to the sample rate of 10us, it is assured that only one sample canoccur while the signal is within the undefined area, and no incorrect transition will bedetected. For inputs which are connected to a peripheral function, e.g. capture inputs, thesample rate is determined by the clock cycle of the peripheral unit. In the case of theCAPCOM unit this means a sample rate of 400ns @ 20MHz CPU clock. This requiresinput signals to pass through the undefined area within these 400ns in order to avoidmultiple capture events.
標(biāo)簽：
C16x
微控制器
輸入信號(hào)
時(shí)序圖
上傳時(shí)間：
2014-04-02
上傳用戶：han_zh
-
設(shè)計(jì)一種應(yīng)用于某全地形ATV車載武器裝置中的中控系統(tǒng)，該系統(tǒng)設(shè)計(jì)是以TMS320F2812型DSP為核心，采用模塊化設(shè)計(jì)思想，對(duì)其硬件部分進(jìn)行系統(tǒng)設(shè)計(jì)，能夠完成對(duì)武器裝置高低、回轉(zhuǎn)方向的運(yùn)動(dòng)控制，實(shí)現(xiàn)靜止或行進(jìn)狀態(tài)中對(duì)目標(biāo)物的測(cè)距，自動(dòng)瞄準(zhǔn)以及按既定發(fā)射模式發(fā)射彈丸和各項(xiàng)安全性能檢測(cè)等功能。通過編制相應(yīng)的軟件，對(duì)其進(jìn)行系統(tǒng)調(diào)試，驗(yàn)證了該設(shè)計(jì)運(yùn)行穩(wěn)定。
Abstract:
A central control system applied to an ATV vehicle weapons is designed. The system design is based on TMS320F2812 DSP as the core， uses modular design for its hardware parts. The central control system can complete the motion control of the level of weapons and equipment， rotation direction， to achieve a state of static or moving objects on the target ranging， auto-targeting and according to the established target and the projectile and the launch of the security performance testing and other functions. Through the development of appropriate software and to carry out system testing to verify the stability of this design and operation.
標(biāo)簽：
ATV-ATT
DSP
中控系統(tǒng)
上傳時(shí)間：
2013-11-02
上傳用戶：jshailingzzh
-
A Computer-On-Module, or COM, is a Module with all components necessary for a bootable host computer, packaged as a super component. A COM requires a Carrier Board to bring out I/O and to power up. COMs are used to build single board computer solutions and offer OEMs fast time-to-market with reduced development cost. Like integrated circuits, they provide OEMs with significant freedom in meeting form-fit-function requirements. For all these reasons the COM methodology has gained much popularity with OEMs in the embedded industry. COM Express® is an open industry standard for Computer-On-Modules. It is designed to be future proof and to provide a smooth transition path from legacy parallel interfaces to LVDS (Low Voltage Differential Signaling) interfaces. These include the PCI bus and parallel ATA on the one hand and PCI Express and Serial ATA on the other hand.
標(biāo)簽：
PICMG_COM
COMe
上傳時(shí)間：
2013-11-05
上傳用戶：Wwill
-
The #1 Step-by-Step Guide to labviewNow Completely Updated for labview 8!
Master labview 8 with the industry's friendliest, most intuitive tutorial: labview for Everyone, Third Edition. Top labview experts Jeffrey Travis and Jim Kring teach labview the easy way: through carefully explained, step-by-step examples that give you reusable code for your own projects!
This brand-new Third Edition has been fully revamped and expanded to reflect new features and techniques introduced in labview 8. You'll find two new chapters, plus dozens of new topics, including Project Explorer, AutoTool, XML, event-driven programming, error handling, regular expressions, polymorphic VIs, timed structures, advanced reporting, and much more. Certified labview Developer (CLD) candidates will find callouts linking to key objectives on NI's newest exam, making this book a more valuable study tool than ever.
Not just what to d why to do it!
Use labview to build your own virtual workbench
Master labview's foundations: wiring, creating, editing, and debugging VIs; using controls and indicators; working with data structures; and much more
Learn the "art" and best practices of effective labview development
NEW: Streamline development with labview Express VIs
NEW: Acquire data with NI-DAQmx and the labview DAQmx VIs
NEW: Discover design patterns for error handling, control structures, state machines, queued messaging, and more
NEW: Create sophisticated user interfaces with tree and tab controls, drag and drop, subpanels, and more
Whatever your application, whatever your role, whether you've used labview or not, labview for Everyone, Third Edition is the fastest, easiest way to get the results you're after!
標(biāo)簽：
Everyone
LabVIEW
for
英文
上傳時(shí)間：
2013-10-14
上傳用戶：shawvi
-
6小時(shí)學(xué)會(huì)labview,
labview Six Hour Course – Instructor Notes
This zip file contains material designed to give students a working knowledge of labview in a 6 hour timeframe. The contents are:
Instructor Notes.doc – this document.
labviewIntroduction-SixHour.ppt – a PowerPoint presentation containing screenshots and notes on the topics covered by the course.
Convert C to F (Ex1).vi – Exercise 1 solution VI.
Convert C to F (Ex2).vi – Exercise 2 solution subVI.
Thermometer-DAQ (Ex2).vi – Exercise 2 solution VI.
Temperature Monitor (Ex3).vi – Exercise 3 solution VI.
Thermometer (Ex4).vi – Exercise 4 solution subVI.
Convert C to F (Ex4).vi – Exercise 4 solution subVI.
Temperature Logger (Ex4).vi – Exercise 4 solution VI.
Multiplot Graph (Ex5).vi – Exercise 5 solution VI.
Square Root (Ex6).vi – Exercise 6 solution VI.
State Machine 1 (Ex7).vi – Exercise 7 solution VI.
The slides can be presented in two three hour labs, or six one hour lectures. Depending on the time and resources available in class, you can choose whether to assign the exercises as homework or to be done in class. If you decide to assign the exercises in class, it is best to assign them in order with the presentation. This way the students can create VI’s while the relevant information is still fresh. The notes associated with the exercise slide should be sufficient to guide the students to a solution. The solution files included are one possible solution, but by no means the only solution.
標(biāo)簽：
labview
上傳時(shí)間：
2013-10-13
上傳用戶：zjwangyichao
-
Agilent AN 154 S-Parameter Design Application Note S參數(shù)的設(shè)計(jì)與應(yīng)用
The need for new high-frequency, solid-state circuitdesign techniques has been recognized both by microwaveengineers and circuit designers. These engineersare being asked to design solid state circuitsthat will operate at higher and higher frequencies.The development of microwave transistors andAgilent Technologies’ network analysis instrumentationsystems that permit complete network characterizationin the microwave frequency rangehave greatly assisted these engineers in their work.The Agilent Microwave Division’s lab staff hasdeveloped a high frequency circuit design seminarto assist their counterparts in R&D labs throughoutthe world. This seminar has been presentedin a number of locations in the United States andEurope.From the experience gained in presenting this originalseminar, we have developed a four-part videotape, S-Parameter Design Seminar. While the technologyof high frequency circuit design is everchanging, the concepts upon which this technologyhas been built are relatively invariant.The content of the S-Parameter Design Seminar isas follows:
標(biāo)簽：
S參數(shù)
上傳時(shí)間：
2013-12-19
上傳用戶：aa54
