Universal Serial Bus (USB) is a communications architecture that gives a personal computer (PC) the ability to interconnect a variety of devices using a simple four- wire cable. The USB is actually a two-wire serial communication link that runs at either 1.5 or 12 megabits per second (mbs). USB protocols can configure devices at startup or when they are plugged in at run time. These devices are broken into various device classes. Each device class defines the common behavior and protocols for devices that serve similar functions. Some examples of USB device classes are shown in the following table
标签： communications architecture Universal computer
上传时间： 2015-12-08
上传用户：stvnash
water temperature control system uses the Single Chip Microcomputer to carry on temperature real-time gathering and controling. DS18B20, digitized temperature sensor, provides the temperature signal by "a main line". In -10～+85℃ the scope, DS18B20’s inherent measuring accuracy is 0.5 ℃. The water temperature real-time control system uses the electricity nichrome wire carring on temperature increiseament and operates the electric fan to realize the temperature decrease control. The system has the higher measuring accuracy and the control precision, it also can complete the elevation of temperature and the temperature decrease control.
标签： temperature Microcomputer real-tim control
上传时间： 2015-12-10
上传用户：nairui21
An AHB system is made of masters slaves and interconnections. A general approach to include all possible "muxed" implementation of multi layered AHB systems and arbitrated AHB ones can be thought as an acyclic graph where every source node is a master, every destination node is a slave and every internal node is an arbiter there must be one and only one arc exiting a master and one or more entering a slave (single slave verus multi-slave or arbitrated slave) an arbiter can have as many input and output connections as needed. A bridge is a special node that collapses one or more slave nodes and a master node in a new "complex" node.
标签： interconnections approach general include
上传时间： 2015-12-12
上传用户：lyy1234
In a preemptive priority based RTOS, priority inversion problem is among the major sources of deadline violations. Priority inheritance protocol is one of the approaches to reduce priority inversion. Unfortunately, RTOS like uC/OS can’t support priority inheritance protocol since it does not allow kernel to have multiple tasks at the same priority. Although it has different ways to avoid priority inversion such as priority ceiling protocol, developers still have some difficulties in programming real time applications with it. In this paper, we redesign the uC/OS kernel to provide the ability to support round robin scheduling and implement priority inheritance semaphore on the modified kernel. As result, we port new kernel with priority inheritance semaphore to evaluation board, and evaluate the execution time of each of the kernel service as well as verify the operations of our implementation.
标签： priority preemptive inversion problem
上传时间： 2015-12-14
上传用户：气温达上千万的
As the Hardware Description Language (HDL) enhancement activities have increased over the past year, so too has the complexity in determining which language(s) are the best tools for designers and organizations to continue using or to adopt. Many designers and organizations are contemplating whether they should switch from one HDL to another.
标签： Description enhancement activities the
上传时间： 2015-12-15
上传用户：sunjet
As the Hardware Description Language (HDL) enhancement activities have increased over the past year, so too has the complexity in determining which language(s) are the best tools for designers and organizations to continue using or to adopt. Many designers and organizations are contemplating whether they should switch from one HDL to another.
标签： Description enhancement activities the
上传时间： 2015-12-15
上传用户：SimonQQ
FuncPlotter is a combined Java application and applet for displaying two-dimensional plots of explicit functions in one variable (ie, FuncPlotter plots functions of the form y = f(x), where f(x) is composed from common mathematical operators).
标签： two-dimensional FuncPlotter application displaying
上传时间： 2015-12-16
上传用户：妄想演绎师
LCDScreen is a couple of Delphi component which simulate a dot-LCD multilines screen. It is fully customizable and has animation and special effects capabilities for the displayed text. TLCDScreen is the display component and TLCDAnimator the animation one. Both have build-in Property editor making easier the development at design-time.
标签： multilines LCDScreen component simulate
上传时间： 2015-12-23
上传用户：invtnewer
New users and old of optimization in MATLAB will find useful tips and tricks in this document, as well as examples one can use as templates for their own problems. Use this tool by editing the file optimtips.m, then execute blocks of code in cell mode from the editor, or best, publish the file to HTML. Copy and paste also works of course. Some readers may find this tool valuable if only for the function pleas - a partitioned least squares solver based on lsqnonlin. This is a work in progress, as I fully expect to add new topics as I think of them or as suggestions are made. Suggestions for topics I ve missed are welcome, as are corrections of my probable numerous errors. The topics currently covered are listed below
标签： optimization and document MATLAB
上传时间： 2015-12-24
上传用户：佳期如梦
This example streams input from a ADC source to a DAC. An analog signal is acquired block-by-block into SDRAM from the ADC (an AD9244 in this example). The frames are then output with a one-frame delay to the DAC (an AD9744 in this example). In this example, no processing is done on the frames. They are passed unaltered.
标签： block-by-block acquired example streams
上传时间： 2015-12-29
上传用户：bjgaofei
