//****************************************************************************************** // PIC12F1822 Sample Program // Project : // Program Name : // Programer : // Create date : Version 1.0 H24.04.10 // History : // Laungage : HI_TECH PICC C Laungage Version 9.70 //****************************************************************************************** // (1)Description // OSC : Internal OSC 16MHz //****************************************************************************************** #include __CONFIG( FOSC_INTOSC & WDTE_OFF & PWRTE_OFF & MCLRE_OFF & CP_OFF & CPD_OFF & BOREN_OFF & CLKOUTEN_OFF & IESO_OFF & FCMEN_OFF ); __CONFIG( WRT_OFF & PLLEN_OFF & STVREN_OFF & BORV_27 & LVP_OFF ) ; // #define PI_NORMAL 0 #define PI_FAILER 1 // void InitUART(void); char SendUART(unsigned char); char RecUART(unsigned char *); void SendUART_s(char *); void main() { unsigned char IO_data; char Init_msg[]=" PIC12F1822 Connected OK> "; // ***************************** // 1.Initialized Segment // ***************************** // (1)Define OSC (16MHz, IntOSC) OSCCON = 0b11111010; // (2)Define ANSELA (ALL Digital Port) ANSELA = 0x00; // (3)Define I/O port TRISA = 0b11111111; // (4)Define APFCON Register // APFCON:RXDTSEL.SDOSEL,SSSEL,---,T1GSEL,TXCKSEL,P1BSEL,CCP1SEL // BSF APFCON,RXDTSEL ; RX ==> RA5 // BSF APFCON,TXCKSEL ; TX ==> RA4 APFCON0bits.RXDTSEL = 1; APFCON0bits.TXCKSEL = 1; // (5)Initialized EUART InitUART(); // (6)Demo Message SendUART_s(Init_msg); // ***************************** // 2.Program main // ***************************** // (1)Main loop while(1){ RecUART(&IO_data); SendUART(IO_data); } } //****************************************************************************************** // Function Name : SendUART_s // Title : Send UART String // Input : // Output : //****************************************************************************************** void SendUART_s(char *put_string) { while(*put_string!=0x00){ SendUART(*put_string); put_string++; } } //****************************************************************************************** // Program : InitUART // Title : Initialize UART // Input : // Output : // Description : Fosc:16MHz, Baud Rate:9600BPS, 16-bit Baud Rate //****************************************************************************************** void InitUART(void){ // ******************************************************* // 1.Define TXSTA(TRANSMIT STATUS AND CONTROL) Register // TXSTA(7) CSRC: Clock Source Select bit // Asynchronous mode:Donft care // TXSTA(6) TX9: 9-bit Transmit Enable bit // 1 = Selects 9-bit transmission // 0 = Selects 8-bit transmission // TXSTA(5) TXEN: Transmit Enable bit(1) // 1 = Transmit enabled // 0 = Transmit disabled // TXSTA(4) SYNC: EUSART Mode Select bit // 1 = Synchronous mode // 0 = Asynchronous mode // TXSTA(3) SENDB: Send Break Character bit // Asynchronous mode: // 1 = Send Sync Break on next transmission (cleared by hardware upon completion) // 0 = Sync Break transmission completed // TXSTA(2) BRGH: High Baud Rate Select bit // Asynchronous mode: // 1 = High speed // 0 = Low speed // TXSTA(1) TRMT: Transmit Shift Register Status bit // 1 = TSR empty // 0 = TSR full // TXSTA(0) TX9D: Ninth bit of Transmit Data // Can be address/data bit or a parity bit. // ******************************************************* TXSTA = 0b00100100; // ******************************************************* // 2.Define RCSTA(RECEIVE STATUS AND CONTROL) Register // RCSTA(7) SPEN: Serial Port Enable bit // 1 = Serial port enabled (configures RX/DT and TX/CK pins as serial port pins) // 0 = Serial port disabled (held in Reset) // RCSTA(6) RX9: 9-bit Receive Enable bit // 1 = Selects 9-bit reception // 0 = Selects 8-bit reception // RCSTA(5) SREN: Single Receive Enable bit // Asynchronous mode: // Donft care // RCSTA(4) CREN: Continuous Receive Enable bit // Asynchronous mode: // 1 = Enables receiver // 0 = Disables receiver // RCSTA(3) ADDEN: Address Detect Enable bit // Asynchronous mode 9-bit (RX9 = 1): // 1 = Enables address detection, enable interrupt and load the receive buffer when RSR<8> is set // 0 = Disables address detection, all bytes are received and ninth bit can be used as parity bit // Asynchronous mode 8-bit (RX9 = 0): // Donft care // RCSTA(2) FERR: Framing Error bit // 1 = Framing error (can be updated by reading RCREG register and receive next valid byte) // 0 = No framing error // RCSTA(1) OERR: Overrun Error bit // 1 = Overrun error (can be cleared by clearing bit CREN) // 0 = No overrun error // RCSTA(0) RX9D: Ninth bit of Received Data // This can be address/data bit or a parity bit and must be calculated by user firmware. // ******************************************************* RCSTA = 0b10010000; // ******************************************************* // 3.Define BAUDCON(BAUD RATE CONTROL) Register // BAUDCON(7) ABDOVF: Auto-Baud Detect Overflow bit // Asynchronous mode: // 1 = Auto-baud timer overflowed // 0 = Auto-baud timer did not overflow // BAUDCON(6) RCIDL: Receive Idle Flag bit // Asynchronous mode: // 1 = Receiver is Idle // 0 = Start bit has been detected and the receiver is active // BAUDCON(5) Unimplemented: Read as e0f // BAUDCON(4) SCKP: Synchronous Clock Polarity Select bit // Asynchronous mode: // 1 = Transmit inverted data // 0 = Transmit non-inverted data // BAUDCON(3) BRG16: 16-bit Baud Rate Generator bit // 1 = 16-bit Baud Rate Generator is used (SPBRGH:SPBRG) // 0 = 8-bit Baud Rate Generator is used (SPBRG) // BAUDCON(2) Unimplemented: Read as e0f // BAUDCON(1) WUE: Wake-up Enable bit // Asynchronous mode: // 1 = Receiver is waiting for a falling edge. No character will be received but RCIF will be set on // the falling edge. WUE will automatically clear on the rising edge. // 0 = Receiver is operating normally // BAUDCON(0) ABDEN: Auto-Baud Detect Enable bit // Asynchronous mode: // 1 = Auto-Baud Detect mode is enabled (clears when auto-baud is complete) // 0 = Auto-Baud Detect mode is disabled // ******************************************************* BAUDCON = 0b00001000; // ******************************************************* // 3.Define BRG(EUSART Baud Rate Generator Register) Register // ******************************************************* // BRG = 16000000(Hz)/4/9600(BPS)-1 ==> 0d0416 ==> 0x1A0 // (1)Define SPBRGH(EUSART Baud Rate Generator Register, High Byte) Register SPBRGH = 0x01; // (2)Define SPBRG(EUSART Baud Rate Generator Register, Low Byte) Register SPBRG = 0xA0; } //****************************************************************************************** // Program : RecUART // Title : Recive UART // Input : // Output : //****************************************************************************************** char RecUART(unsigned char *IO_data) { unsigned char status; // **************************** // 1.Check Recvive Flag // **************************** // (1)Clear RCIF PIR1 = PIR1 & 0b11111011; // (2)Check RCIF while(1){ status = PIR1 & 0x20; if(status != 0x00)break; } // **************************** // 2.Check error // **************************** status = RCSTA & 0x06; //0000,0110 RCSTA(FERR,OERR) if(status != 0x00){ *IO_data = 0x00; return(PI_FAILER); } // **************************** // 3.Set Recive Data // **************************** *IO_data = RCREG; return(PI_NORMAL); } //****************************************************************************************** // Program : SendUART // Title : Send UART // Input : // Output : //****************************************************************************************** char SendUART(unsigned char IO_data) { unsigned char status; // *************************** // 1.Check Send Flag // *************************** while(1){ status = TXSTA & 0x02; //0000,0010 TXSTA(TRMT) if(status != 0x00)break; } // *************************** // 2.Set data // *************************** TXREG = IO_data; return(PI_NORMAL); }