1、X5045組成的看門(mén)狗電路及51讀寫(xiě)x5045存儲(chǔ)器的程序時(shí)間：2011-05-05 23:35:06 來(lái)源： 作者：X5045是一種集看門(mén)狗、電壓監(jiān)控和串行EEPROM 三種功能于一身的可編程控制電路.特別適合應(yīng)用在需要少量存儲(chǔ)器,并對(duì)電路板空間需求較高場(chǎng)合,X5045具有電壓監(jiān)控功能,可以保護(hù)系統(tǒng)免受低電壓的影響，當(dāng)電源電壓降到允許范圍(4.2V)以下時(shí)，系統(tǒng)將復(fù)位，直到電源電壓返回到穩(wěn)定值為止。X5045的存儲(chǔ)器與CPU 通過(guò)串行通信方式接口(SPI)，可以存放512個(gè)字節(jié)數(shù)據(jù).可擦寫(xiě)100萬(wàn)次,數(shù)據(jù)可保存100年.下圖是X5045與具有手動(dòng)復(fù)位的8051微控制器的連接注意：圖上的芯片寫(xiě)

2、著是X5043，實(shí)際上這是X5045的接法下邊是51讀寫(xiě)x5045存儲(chǔ)器的程序/x5045和51的連接方法sbit CS = P10; sbit SO = P13;sbit SI = P11;sbit SCK = P12; /定義寄存器指令#define WREN 0x06 / 寫(xiě)入使能指令(WREN)#define WRDI 0x04 / 寫(xiě)入禁止指令(WRDI)#define WRSR 0x01 / 寫(xiě)入狀態(tài)寄存器指令(WRSR)#define RDSR 0x05 / 讀取狀態(tài)寄存器指令(RDSR)#define WRITE 0x02 / 寫(xiě)入存儲(chǔ)器指令(WRITE)#define REA

3、D 0x03 / 讀取存儲(chǔ)器指令(READ) #define STATUS_REG 0x00 / 要寫(xiě)入到狀態(tài)寄存器的值 #define MAX_POLL 0x99 / 最在查詢(xún)次數(shù)m number ofvoid outbyte(unsigned char write_data) unsigned char i; for(i = 0; i 8; i+) SCK = 0; SI = (bit)(write_data & 0x80); /傳送一個(gè)位到SI write_data = 1; SCK = 1; SI = 0; unsigned char inbyte() unsigned char i;

4、 unsigned char read_data=0;for(i = 0; i 8; i+) SCK = 0; read_data = 1; SCK = 1; read_data |= (unsigned char)SO; return read_data;void wren_cmd() CS = 0; outbyt(WREN); / 傳送寫(xiě)入使能指令 CS = 1; void wrdi_cmd() CS = 0; outbyt(WRDI); / 傳送寫(xiě)入禁止指令 CS = 1; unsigned char rdsr_cmd() unsigned char status; CS = 0; ou

5、tbyt(RDSR); / 傳送狀態(tài)寄存器讀取指令 status = inbyt(); / 讀取狀態(tài)寄存 CS = 1; return status; void wip_poll() unsigned char i; / 設(shè)置最大的查詢(xún)次數(shù)/ 如果WIP位為1并且未達(dá)到最大查詢(xún)次數(shù), 則繼續(xù)查詢(xún)/ 如果WIP位為0, 則寫(xiě)入周期完成, 返回 for(i = 0; i MAX_POLL; i+) if(rdsr_cmd() & 0x01) / 讀取狀態(tài)寄存器 continue; return; void wrsr_cmd() CS = 0; outbyt(WRSR); / 傳送狀態(tài)寄存器寫(xiě)入指令

6、 outbyt(STATUS_REG); / 傳送要寫(xiě)入的數(shù)據(jù) CS = 1; wip_poll(); / 檢測(cè)寫(xiě)入進(jìn)度void byte_write(unsigned int addr,unsigned char dat) wren_cmd(); CS = 0; if(addr & 0x100) outbyt(WRITE | 0x08); /傳送寫(xiě)入指令和地址最高位1 else outbyt(WRITE); / 傳送寫(xiě)入指令和地址最高位0 outbyt(addr); / 傳送地址低字節(jié) outbyt(dat); / 傳送數(shù)據(jù)字節(jié)CS = 1; wip_poll(); / 檢測(cè)寫(xiě)入進(jìn)度 uns

7、igned char byte_read(unsigned int addr) unsigned char read_data; CS = 0; if(addr & 0x100) outbyt(READ | 0x08);/ 傳送讀取指令和地址最高位1 else outbyt(READ); / 傳送讀取指令和地址最高位0outbyt(addr); / 傳送地址低字節(jié)read_data = inbyt(); / 讀取字節(jié) CS = 1; return read_data;void rst_wdog() CS = 0; _nop_();_nop_(); CS = 1; void init_seria

8、lcomm(void) TMOD = 0x21; / 定時(shí)器1工作于8位自動(dòng)重載模式, 用于產(chǎn)生波特率 / 定時(shí)器0工作于16位模式, 用于定時(shí)TH1 = 0xFD; / 波特率9600 TL1 = 0xFD; SCON = 0x50; / 設(shè)定串行口工作方式 PCON &= 0xef; / 波特率不倍增 TR1 = 1; / 啟動(dòng)定時(shí)器1 void send_char_com(unsigned char ch) /向串口發(fā)送一個(gè)字符 SBUF=ch; while(!TI); TI=0; void main(void) unsigned char Temp,tdat;init_serialcomm(); while(1) /這里演示讀出和寫(xiě)入 EEPROM for (Tem