//芯片資料請到www.elecfans.com查找 //DS1820 C51 子程序//這里以11.0592M晶體為例,不同的晶體速度可能需要調(diào)整延時(shí)的時(shí)間//sbit DQ =P2^1;//根據(jù)實(shí)際情況定義端口 typedef unsigned char byte;typedef unsigned int word; //延時(shí)void delay(word useconds){ for(;useconds>0;useconds--);} //復(fù)位byte ow_reset(void){ byte presence; DQ = 0; //pull DQ line low delay(29); // leave it low for 480us DQ = 1; // allow line to return high delay(3); // wait for presence presence = DQ; // get presence signal delay(25); // wait for end of timeslot return(presence); // presence signal returned} // 0=presence, 1 = no part //從 1-wire 總線上讀取一個字節(jié)byte read_byte(void){ byte i; byte value = 0; for (i=8;i>0;i--) { value>>=1; DQ = 0; // pull DQ low to start timeslot DQ = 1; // then return high delay(1); //for (i=0; i<3; i++); if(DQ)value|=0x80; delay(6); // wait for rest of timeslot } return(value);} //向 1-WIRE 總線上寫一個字節(jié)void write_byte(char val){ byte i; for (i=8; i>0; i--) // writes byte, one bit at a time { DQ = 0; // pull DQ low to start timeslot DQ = val&0x01; delay(5); // hold value for remainder of timeslot DQ = 1; val=val/2; } delay(5);} //讀取溫度char Read_Temperature(void){ union{ byte c[2]; int x; }temp; ow_reset(); write_byte(0xCC); // Skip ROM write_byte(0xBE); // Read Scratch Pad temp.c[1]=read_byte(); temp.c[0]=read_byte(); ow_reset(); write_byte(0xCC); //Skip ROM write_byte(0x44); // Start Conversion return temp.x/2;}
上傳時(shí)間: 2013-11-03
上傳用戶:hongmo
#include <reg51.h>#include<intrins.h> #define BUSY1 (DQ1==0) sbit DQ1 = P0^4; unsigned char idata TMP; unsigned char idata TMP_d; unsigned char f; void wr_ds18_1(char dat);unsigned char rd_ds18_1(); /***************延時(shí)程序,單位us,大于10us*************/void time_delay(unsigned char time){ time=time-10; time=time/6; while(time!=0)time--;} /*****************************************************//* reset ds18b20 *//*****************************************************/void ds_reset_1(void){ unsigned char idata count=0; DQ1=0; time_delay(240); time_delay(240); DQ1=1; return;}
上傳時(shí)間: 2013-10-29
上傳用戶:sssnaxie
PLC TM卡開發(fā)系統(tǒng)匯編程序(ATM8051) ;***************** 定義管腳*************************SCL BIT P1.0SDA BIT P1.1GC BIT P1.2BZ BIT P3.6LEDI BIT P1.4LEDII BIT P1.5OK BIT 20H.1OUT1 BIT P1.3OUT2 BIT P1.0OUT3 BIT P1.1RXD BIT P3.0TXD BIT P3.1PCV BIT P3.2WPC BIT P3.3RPC BIT P3.5LEDR BIT P3.4LEDL BIT P3.6TM BIT P3.7;********************定義寄存器***********************ROMDTA EQU 30H;NUMBY EQU 61H;SLA EQU 60H;MTD EQU 2FH;MRD EQU 40H;TEMP EQU 50H;;ORG 00H;;INDEX:MOV P1, #00H;MOV P2, #0FFHMOV MTD ,#00HCALL REEMOV R0,40HCJNE R0,#01,NO;MOV P2,#1CHLJMP VIMEN MOV P2,#79HACALL TOUCHRESET ;JNC NO ;CALL READTM ;CJNE A,#01H,NO;NOPMOV MTD, #00HCALL WEENOPMOV P2,#4AHSETB BZCALL TIMECLR BZMOV PCON, #0FFHVIME:CALL TIME1CALL TOUCHRESETJNC VIMECALL READTMCJNE A, #01H,VIME;NOPNOPNOPIII: MOV MTD,#00HCALL REECALL BBJNB OK,NO1LJMP ZHUNO1:MOV MTD,#10H
上傳時(shí)間: 2014-03-24
上傳用戶:448949
用單片機(jī)配置FPGA—PLD設(shè)計(jì)技巧 Configuration/Program Method for Altera Device Configure the FLEX Device You can use any Micro-Controller to configure the FLEX device–the main idea is clocking in ONE BITof configuration data per CLOCK–start from the BIT 0The total Configuration time–e.g. 10K10 need 15K byte configuration file•calculation equation–10K10* 1.5= 15Kbyte–configuration time for the file itself•15*1024*8*clock = 122,880Clock•assume the CLOCK is 4MHz•122,880*1/4Mhz=30.72msec
標(biāo)簽: FPGA PLD 用單片機(jī) 設(shè)計(jì)技巧
上傳時(shí)間: 2013-10-09
上傳用戶:a67818601
自動檢測80C51 串行通訊中的波特率本文介紹一種在80C51 串行通訊應(yīng)用中自動檢測波特率的方法。按照經(jīng)驗(yàn),程序起動后所接收到的第1 個字符用于測量波特率。這種方法可以不用設(shè)定難于記憶的開關(guān),還可以免去在有關(guān)應(yīng)用中使用多種不同波特率的煩惱。人們可以設(shè)想:一種可靠地實(shí)現(xiàn)自動波特檢測的方法是可能的,它無須嚴(yán)格限制可被確認(rèn)的字符。問題是:在各種的條件下,如何可以在大量允許出現(xiàn)的字符中找出波特率的定時(shí)間隔。顯然,最快捷的方法是檢測一個單獨(dú)位時(shí)間(single bit time),以確定接收波特率應(yīng)該是多少。可是,在RS-232 模式下,許多ASCII 字符并不能測量出一個單獨(dú)位時(shí)間。對于大多數(shù)字符來說,只要波特率存在合理波動(這里的波特率是指標(biāo)準(zhǔn)波特率),從起始位到最后一位“可見”位的數(shù)據(jù)傳輸周期就會在一定范圍內(nèi)發(fā)生變化。此外,許多系統(tǒng)采用8 位數(shù)據(jù)、無奇偶校驗(yàn)的格式傳輸ASCII 字符。在這種格式里,普通ASCII 字節(jié)不會有MSB 設(shè)定
標(biāo)簽: 80C51 自動檢測 單片機(jī) 串行通訊
上傳時(shí)間: 2013-10-15
上傳用戶:shirleyYim
Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their productsor to discontinue any product or service without notice, and advise customers to obtain the latestversion of relevant information to verify, before placing orders, that information being relied onis current and complete. All products are sold subject to the terms and conditions of sale suppliedat the time of order acknowledgement, including those pertaining to warranty, patentinfringement, and limitation of liability
上傳時(shí)間: 2013-12-26
上傳用戶:凌云御清風(fēng)
This white paper discusses how market trends, the need for increased productivity, and new legislation have accelerated the use of safety systems in industrial machinery. This TÜV-qualified FPGA design methodology is changing the paradigms of safety designs and will greatly reduce development effort, system complexity, and time to market. This allows FPGA users to design their own customized safety controllers and provides a significant competitive advantage over traditional microcontroller or ASIC-based designs. Introduction The basic motivation of deploying functional safety systems is to ensure safe operation as well as safe behavior in cases of failure. Examples of functional safety systems include train brakes, proximity sensors for hazardous areas around machines such as fast-moving robots, and distributed control systems in process automation equipment such as those used in petrochemical plants. The International Electrotechnical Commission’s standard, IEC 61508: “Functional safety of electrical/electronic/programmable electronic safety-related systems,” is understood as the standard for designing safety systems for electrical, electronic, and programmable electronic (E/E/PE) equipment. This standard was developed in the mid-1980s and has been revised several times to cover the technical advances in various industries. In addition, derivative standards have been developed for specific markets and applications that prescribe the particular requirements on functional safety systems in these industry applications. Example applications include process automation (IEC 61511), machine automation (IEC 62061), transportation (railway EN 50128), medical (IEC 62304), automotive (ISO 26262), power generation, distribution, and transportation. 圖Figure 1. Local Safety System
標(biāo)簽: FPGA 安全系統(tǒng)
上傳時(shí)間: 2013-11-05
上傳用戶:維子哥哥
Introduction to Xilinx Packaging Electronic packages are interconnectable housings for semiconductor devices. The major functions of the electronic packages are to provide electrical interconnections between the IC and the board and to efficiently remove heat generated by the device. Feature sizes are constantly shrinking, resulting in increased number of transistors being packed into the device. Today's submicron technology is also enabling large-scale functional integration and system-on-a-chip solutions. In order to keep pace with these new advancements in silicon technologies, semiconductor packages have also evolved to provide improved device functionality and performance. Feature size at the device level is driving package feature sizes down to the design rules of the early transistors. To meet these demands, electronic packages must be flexible to address high pin counts, reduced pitch and form factor requirements. At the same time,packages must be reliable and cost effective.
上傳時(shí)間: 2013-10-22
上傳用戶:ztj182002
本文詳細(xì)介紹了有關(guān)FPGA的開發(fā)流程,對初學(xué)者會有很大的指導(dǎo)作用。
標(biāo)簽: Quest Time FPGA 開發(fā)流程
上傳時(shí)間: 2013-11-18
上傳用戶:simonpeng
In the past decade, the size and complexity of manyFPGA designs exceeds the time and resourcesavailable to most design teams, making the use andreuse of Intellectual Property (IP) imperative.However, integrating numerous IP blocks acquiredfrom both internal and external sources can be adaunting challenge that often extends, rather thanshortens, design time. As today's designs integrateincreasing amounts of functionality, it is vital thatdesigners have access to proven, up-to-date IP fromreliable sources.
上傳時(shí)間: 2013-11-15
上傳用戶:lyy1234
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