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1、英文资料翻译（一）英语文献Ramtron introduces the Versa Mix 8051 family of highly integrated mixed-signal microcontrollers for the embedded data acquisition market。Ramtron also introduces Versa 8051 family of low-cost, drop-in replacement 8051 microcontrollers.Colorado Springs, USA 14th December 2005. Ramtron Int
2、ernational Corporation (Nasdaq: RMTR), the leading supplier of non-volatile ferroelectric semiconductor products, has launched the Versa Mix 8051 family (VMX51C1xxx) of mixed-signal microcontrollers - single-chip solutions for a diverse range of signal conditioning, data acquisition, processing and
3、control applications in the industrial, medical, consumer, instrumentation and Autom-otive markets. Ramtron is also introducing its Versa 8051 Family (VRS51x1xxx/5xx) of low-cost, industry standard, 8051-based drop-in MCUs with up to128KB ISP/IAP Flash, designed to simplify device migration.About th
4、e Versa Mix 8051 family：The Versa Mix (VMX51C1020/1016) is a highly integrated, high-performance family of mixed-signal 8051 microcontrollers with DSP capabilities, featuring a comprehensive set of on-chip peripherals for a complete data acquisition SoC. The VMX51C1xxx features a single-cycle 8051 p
5、rocessor that provides an average of eight times more processing power than standard 8051s for increased MIPS and efficiency. The device integrates an enhanced MULT/ACCU unit with 32-bit barrel shifter, 56KB of Flash and 1280 bytes of RAM. Peripherals include up to 28 general purpose I/Os, 3 timers/
6、counters, an SPI, 2 UARTs, an IC and an RS-485/RS-422/J1708 compatible transceiver, which enables data transmission over long distances via a twisted pair cable. The VMX51C1xxx operates at 5 volts and is available in QFP-64 (VMX51C1020) and QFP-44 (VMX51C1016) packages.Aimed at control applications
7、that require signal conditioning, the VMX51C1020 also incorporates an array of analog peripherals such as a programmable current source, two digital potentiometers, an analog switch and an uncommitted operational amplifier.The features of the Versa Mix 8051 include:A/D Converter This 5/7-channel, 12
8、-bit A/D converter can operate at up to 10KHz in various modes: automatic, single channel, or sequential conversion.The features of the Versa Mix 8051 include:A/D Converter This 5/7-channel, 12-bit A/D converter can operate at up to 10KHz in various modes: automatic, single channel, or sequential co
9、nversion.Complex DSP operations - The enhanced hardware arithmetic unit performs 16-bit x 16-bit multiplication and 32-bit addition in one cycle. This enables major performance gain over typical 8051 devices when executing mathematical and DSP operations - an ideal feature for applications that requ
10、ire digital filtering or other recursive calculations.Serial Port Interface This fully-configurable master/slave interface can automatically address up to four slave devices and can be configured to handle 1 to +32-bit data transactions. UART with Baud Rate Generator UARTs operate at over 460kbps an
11、d each incorporate a 10-bit baud rate generator freeing up the timers/counters for other uses. UARTs can be connected to the integrated differential transceiver. Timers/CCU units The VMX51C1xxx includes three 16-bit timers and 4 compare and capture units (CCUs). The CCUs can be configured as PWM out
12、puts with 8-bit or 16-bit resolution. The PWMs, when filtered, can be used as D/A converters. Three of the CCUs provide a capture input that can be used to trigger the Timer 2 Capture. Additionally, the device includes input pins and an interrupt on the Port1 Change. Power-saving features - Power sa
13、ving features include a clock control unit, individual power controls for each peripheral and processor IDLE and STOP modesAbout the Versa 8051 family：Ramtron has also introduced the Versa 8051 family (VRS51x1xxx/5xxx) of low-cost, drop-in replacement 8051s that are ideal for a diversity of applicat
14、ions that require small to large amounts of program/data memory with nonvolatile data storage and/or code/field based firmware upgrade capability, coupled with streamlined/comprehensive peripheral support. Versa 8051s include up to 128KB Flash memory and 1KB RAM. Devices operate at either 3.3 or 5 v
15、olts and are available in 44-pin PLCC/QFP and also 40-pin DIP packages.Development & programming tools：Evaluation and prototype development of Versa Mix 8051 and Versa 8051 MCUs is facilitated through Ramtrons UVK (UniVersaKit) development kit, which ships complete with the Versa Ware programming in
16、terface software, C compiler and assembler.About Ramtron：Ramtron International Corporation, headquartered in Colorado Springs, Colorado, is a fabless semiconductor company that designs, develops and markets specialised semiconductor memory, microcontroller and integrated semiconductor solutions used
17、 in a wide range of product applications and markets worldwide. Additionally, Ramtron works with various leading-edge licensees and manufacturers to bring its technology to market. AN INTRODUCTION OF 8051An 8051 microcontroller, generally speaking, is any microcontroller that has an instruction set
18、compatible with the MCS-51 standard. Intel made the original 8051 microcontroller back in 1980. Since then, dozens of semiconductor firms have chosen the MCS-51 standard for their lines of microcontrollers. When we speak of 8051 we are not just speaking of the Intel 8051, but also any other microcon
19、troller that is compatible with the 8051 (its faster then writing 8052-compatible every time we make reference to it). A derivative microcontroller (or derivative chip) is a term used to refer to any of the hundreds of 8051-compatible microcontrollers produced by dozens of semiconductor firms such a
20、s Dallas Semiconductor, Philips, Atmel, etc. These lines of microcontrollers all use the 8051 core licensed from Intel. The core refers to the instruction set and Special Function Register structure/map. If you have a development toolset that is 8052-compatible, you should be able to use that same t
21、oolset with any derivative chip. Most 8051 developers use a PC with some version of Windows (although some use Unix). You will run your development tools on the PC to edit and compile your 8051 software. Once 8051 software has been compiled, will need to transmit your compiled program to the microco
22、ntroller. How you do this and what hardware you need depends on the derivative chip youre using and your actual circuit design. Traditionally, programs have been burned into an EPROM using an EPROM programmer. The EPROM is subsequently inserted into your circuit and the program is accessed by the mi
23、crocontroller. EPROMs may be erased and re-used by clearing them with an EPROM Eraser (the EPROM is erased by exposing the EPROM to ultra-violet light for 5-10 minutes). An EPROM emulator is often used during the testing or development stages to allow the developer to quickly test code without havin
24、g to constantly burn and erase EPROMs. However, many newer derivative chips include internal EEPROM or Flash memory. These derivatives often include a process of downloading your compiled 8051 program directly into the microcontroller via a serial port. In these cases, the EPROM programmer is unnece
25、ssary.In addition to the hardware , youll need an ASCII editor that allows you to create 8052 source code. You may use programs as simple as EDIT in DOS or NOTEPAD in Windows to advanced software development editors. Whats important is that the program save your code as PURE ASCII-this means no word
26、 processors such as Word or Works. Once youve created your source code, you need a program to compile or assemble this into an Intel HEX file. This software is called an assembler (if it handles assembly language) or a compiler if it handles anything else (C, Basic, Pascal, etc.). These assemblers a
27、nd compilers will generally create anoutput file known as a HEX file. This is essentially the 8051 equivalent of an EXE file. This file is then either downloaded directly to the microcontroller (if your derivative has In-System Programming/Serial Port loading support) or is passed to yet another pro
28、gram which transfers the file to an EPROM using an EPROM programmer.All of these products were designed for PC development-that is to say, your final program is executed on your PC. In the case of 8051 development, your final program will be executed by an 8051 microcontroller. The 8051 is not compa
29、tible with any common PC development tools. Please refer to the Links page for a list of links to companies that offer 8051-compatible tools including assemblers, C, BASIC, and Pascal compilersProbably not too hard. C compilers exist for the 8051, so if you are familiar with C you shouldnt have too
30、much trouble adapting to an 8051 C compiler. The differences are mostly in handling the special features of the 8051 and thats just a matter of reading to learn the idiosyncracies of the 8051。If all you know is Visual Basic, the 8051 may be a challenge for you. Most of what applies to VB-programming
31、 does not apply to 8051 programming. You cant use VB to program the 8051. You cant use VBX or ActiveX controls with the 8051. In fact, there are no textbox, label, listbox or any other kind of control. While you can purchase a BASIC compiler that is compatible with the 8051, you will find it quite p
32、rimitive compared to VisualBasic. In fact, its even less powerful than Microsofts 80s-era QuickBasic.No C+ compiler exists for the 8051. You must use plain old C. C+ uses dynamic memory handling to create and destroy objects. This is generally handled by DOS or the Operating System. No such OS exist
33、s on the 8051. C+ is also usually more memory-hungry, and 8051s normally have less than 64k of program memory available. There is now a C+ precompiler available from Ceibo. This pre-compiler takes C+ code and precompiles it into Keil C where it is actually compiled. The general visitors is that C+ i
34、s not an appropriate language for the 8051 architecture。These three terms refer to three different ways of getting your program concept to run a given processor, each with varying levels of ease in programming and efficiency in execution. An interpreted program is one in which the program must be an
35、alyzed each time the program is run to determine what actions the processor should execute. Since the program is essentially compiled on the fly, program execution is generally slow in comparsion to other options. Code size is often larger, too, since not only is your program held in code memory but
36、 also the kernel which actually interprets and executes your program. Interpreted languages are usually only useful for learning purposes and are seldom used in commercial projects. An example of an interpreted option with the 8051 is 8051-BASIC. An assembler allows you to write your program in asse
37、mbly language which is one step away from pure machine language. The assembler actually translates your assembly program into machine language. A well-written assembly language program will provide the most speed and smallest code size, but writing a program in assembly language is generally conside
38、red to be more advanced and more difficult than writing a similar program in an interpreted or compiled language. Most 8051 programmers work in assembly language (about 52% according to a recent survey). Using assembly language also gives you complete control over what the processor is doing. A comp
39、iler is used when the programmer wishes to write his code in a high-level language, such as C, Pascal, or sometimes Basic. In the 8051 community, C is the most popular compiled language. A compiler translates the source code written in the high-level language to machine language; thus the resulting
40、output is the same as the output of an assembler-pure executable machine code. Most modern compilers are relatively efficient and produce relatively tight code. However, an equivalent C program will almost require more code size than the same program in assembly language-unless the assembly language
41、 program was very poorly written. The advantage to using a high-level language is that more programmers are familiar with C, Pascal, and Basic than are familiar with 8051 assembly language. High-level language programs are also, arguably, easier to read and understand than the same program in assemb
42、ly language and, thus, are often easier to maintain-especially if the program will have to be maintained by someone other than the original programmer(s).Further, modern C compilers often generate highly optimized code that is often more efficient than a typical programmers assembly code, especially
43、 if the programmer has little experience in 8051 assembly language. C compilers for the 8051 are often more expensive than assemblers.Timers are useful, but they are fast. With a standard 8052 running at 12MHZ, the 16-bit timer-which takes the most time of any timer to overflow-will still overflow a
44、bout 15.26 times per second; thats about .06 seconds per overflow. To use a timer to count relatively long periods of times-anything over .06 seconds-will require a little extra code. This is the pefect situation for an interrupt. The idea is to cause the timer to overflow at a known rate and then c
45、ount how many times it overflows. For example, .06 is not a fun number to work with since it is not evenly divisible by a full second. Rather, itd be useful to configure the program such that the timer overflows every .05 seconds. Then, if it has overflowed 20 times you know one second has passed. T
46、his can be done in various ways。Technically, T0_INTERRUPT resets TL0 and TH0 in a not-so-safe way. It is generally recommended that when you change the value of TH0 and/or TL0 that you first stop the timer by clearing TR0. After youve set the two SFRs, you then restart the timer by setting TR0. In t
47、his case, it is not absolutely necessary because the value were setting, is such that there will be no nasty side effects. However, if you were resetting the timer to it would be absolutely necessary to stop the timer. Otherwise, youd first write TL0 to FFh, it would immedaitely overflow back to 00h
48、 and youd write TH0 。 It is depending on the oscillator you are using and the baud rate that you desire, that the formula will give you a fractional answer. For example, if you were using a 12.000MHZ crystal 。Obviously, you cant use a fractional value-youd either have to use 3 or 4. Using 3 would pr
49、oduce a baud rate of 10416, and 4 would produce a baud rate of 7812-neither of which is anything close to 9600. In this case, you could try taking advantage of the SMOD bit. That is, set SMOD and look for a baud rate of about 4800 (which would be doubled to 9600 by setting SMOD). Plugging in 4800 into the above formula we get a TH1 value of 6.5, so wed either have to use 6 or 7. If we use 6, we get a