@DOC_TITLE@ Xmega Application Note usart_example_polled.cGo to the documentation of this file.00001 /* This file has been prepared for Doxygen automatic documentation generation.*/ 00052 #include "usart_driver.h" 00053 #include "avr_compiler.h" 00054 00055 00057 #define USART USARTC0 00058 00059 00061 bool success; 00062 00063 00077 int main(void) 00078 { 00079 00080 /* Variable used to send and receive data. */ 00081 uint8_t sendData; 00082 uint8_t receivedData; 00083 00084 /* This PORT setting is only valid to USARTC0 if other USARTs is used a 00085 * different PORT and/or pins is used. */ 00086 /* PIN3 (TXD0) as output. */ 00087 PORTC.DIRSET = PIN3_bm; 00088 00089 /* PC2 (RXD0) as input. */ 00090 PORTC.DIRCLR = PIN2_bm; 00091 00092 /* USARTC0, 8 Data bits, No Parity, 1 Stop bit. */ 00093 USART_Format_Set(&USART, USART_CHSIZE_8BIT_gc, USART_PMODE_DISABLED_gc, false); 00094 00095 /* Set Baudrate to 9600 bps: 00096 * Use the default I/O clock fequency that is 2 MHz. 00097 * Do not use the baudrate scale factor 00098 * 00099 * Baudrate select = (1/(16*(((I/O clock frequency)/Baudrate)-1) 00100 * = 12 00101 */ 00102 USART_Baudrate_Set(&USART, 12 , 0); 00103 00104 /* Enable both RX and TX. */ 00105 USART_Rx_Enable(&USART); 00106 USART_Tx_Enable(&USART); 00107 00108 00109 /* Assume that everything is OK. */ 00110 success = true; 00111 /* Send data from 255 down to 0*/ 00112 sendData = 255; 00113 while(sendData) { 00114 /* Send one char. */ 00115 do{ 00116 /* Wait until it is possible to put data into TX data register. 00117 * NOTE: If TXDataRegister never becomes empty this will be a DEADLOCK. */ 00118 }while(!USART_IsTXDataRegisterEmpty(&USART)); 00119 USART_PutChar(&USART, sendData); 00120 00121 uint16_t timeout = 1000; 00122 /* Receive one char. */ 00123 do{ 00124 /* Wait until data received or a timeout.*/ 00125 timeout--; 00126 }while(!USART_IsRXComplete(&USART) && timeout!=0); 00127 receivedData = USART_GetChar(&USART); 00128 00129 /* Check the received data. */ 00130 if (receivedData != sendData){ 00131 success = false; 00132 } 00133 sendData--; 00134 } 00135 00136 /* Disable both RX and TX. */ 00137 USART_Rx_Disable(&USART); 00138 USART_Tx_Disable(&USART); 00139 00140 /* If success the program ends up inside the if statment.*/ 00141 if(success){ 00142 while(true); 00143 }else{ 00144 while(true); 00145 } 00146 } @DOC_TITLE@ Generated on Wed Nov 5 10:23:27 2008 for AVRxxxx Application note title by 1.5.5