@DOC_TITLE@ Xmega Application Note usart_example_interrupt.c File ReferenceDetailed Description XMEGA USART interrupt driven driver example source. This file contains an example application that demonstrates the interrupt driven USART driver. The code example sends three bytes, waits for three bytes to be received and tests if the received data equals the sent data. Application note:AVR1307: Using the XMEGA USART DocumentationFor comprehensive code documentation, supported compilers, compiler settings and supported devices see readme.html Author:Atmel Corporation: http://www.atmel.com Support email: [e-mail] Revision1694 Date2008-07-29 14:21:58 +0200 (ti, 29 jul 2008) Copyright (c) 2008, Atmel Corporation All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. 3. The name of ATMEL may not be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. Definition in file usart_example_interrupt.c. #include "usart_driver.h" #include "avr_compiler.h" Include dependency graph for usart_example_interrupt.c: Go to the source code of this file. Defines #define NUM_BYTES   3 #define USART   USARTC0 Functions  ISR (USARTC0_DRE_vect)  Data register empty interrupt service routine.  ISR (USARTC0_RXC_vect)  Receive complete interrupt service routine. int main (void)  Example application. Variables uint8_t receiveArray [NUM_BYTES] uint8_t sendArray [NUM_BYTES] = {0x55, 0xaa, 0xf0} bool success USART_data_t USART_data Define Documentation #define NUM_BYTES   3 Number of bytes to send in test example. Definition at line 55 of file usart_example_interrupt.c. Referenced by main(). #define USART   USARTC0 Define that selects the Usart used in example. Definition at line 57 of file usart_example_interrupt.c. Referenced by main(). Function Documentation ISR ( USARTC0_DRE_vect   )  Data register empty interrupt service routine. Data register empty interrupt service routine. Calls the common data register empty complete handler with pointer to the correct USART as argument. Definition at line 179 of file usart_example_interrupt.c. References USART_DataRegEmpty(). 00180 { 00181 USART_DataRegEmpty(&USART_data); 00182 } Here is the call graph for this function: ISR ( USARTC0_RXC_vect   )  Receive complete interrupt service routine. Receive complete interrupt service routine. Calls the common receive complete handler with pointer to the correct USART as argument. Definition at line 167 of file usart_example_interrupt.c. References USART_RXComplete(). 00168 { 00169 USART_RXComplete(&USART_data); 00170 } Here is the call graph for this function: int main ( void   )  Example application. Example application. This example configures USARTC0 for with the parameters: 8 bit character sizeNo parity1 stop bit9600 Baud This function then sends three bytes and tests if the received data is equal to the sent data. The code can be tested by connecting PC3 to PC2. If the variable 'success' is true at the end of the function, the three bytes have been successfully sent and received. Definition at line 82 of file usart_example_interrupt.c. References NUM_BYTES, receiveArray, sendArray, success, Usart_and_buffer::usart, USART, USART_Baudrate_Set, USART_Format_Set, USART_InterruptDriver_Initialize(), USART_Rx_Enable, USART_RXBuffer_GetByte(), USART_RXBufferData_Available(), USART_RxdInterruptLevel_Set, USART_Tx_Enable, and USART_TXBuffer_PutByte(). 00083 { 00084 /* counter variable. */ 00085 uint8_t i; 00086 00087 /* This PORT setting is only valid to USARTC0 if other USARTs is used a 00088 * different PORT and/or pins are used. */ 00089 /* PC3 (TXD0) as output. */ 00090 PORTC.DIRSET = PIN3_bm; 00091 /* PC2 (RXD0) as input. */ 00092 PORTC.DIRCLR = PIN2_bm; 00093 00094 /* Use USARTC0 and initialize buffers. */ 00095 USART_InterruptDriver_Initialize(&USART_data, &USART, USART_DREINTLVL_LO_gc); 00096 00097 /* USARTC0, 8 Data bits, No Parity, 1 Stop bit. */ 00098 USART_Format_Set(USART_data.usart, USART_CHSIZE_8BIT_gc, 00099 USART_PMODE_DISABLED_gc, false); 00100 00101 /* Enable RXC interrupt. */ 00102 USART_RxdInterruptLevel_Set(USART_data.usart, USART_RXCINTLVL_LO_gc); 00103 00104 /* Set Baudrate to 9600 bps: 00105 * Use the default I/O clock frequency that is 2 MHz. 00106 * Do not use the baudrate scale factor 00107 * 00108 * Baudrate select = (1/(16*(((I/O clock frequency)/Baudrate)-1) 00109 * = 12 00110 */ 00111 USART_Baudrate_Set(&USART, 12 , 0); 00112 00113 /* Enable both RX and TX. */ 00114 USART_Rx_Enable(USART_data.usart); 00115 USART_Tx_Enable(USART_data.usart); 00116 00117 /* Enable PMIC interrupt level low. */ 00118 PMIC.CTRL |= PMIC_LOLVLEX_bm; 00119 00120 /* Enable global interrupts. */ 00121 sei(); 00122 00123 /* Send sendArray. */ 00124 i = 0; 00125 while (i < NUM_BYTES) { 00126 bool byteToBuffer; 00127 byteToBuffer = USART_TXBuffer_PutByte(&USART_data, sendArray[i]); 00128 if(byteToBuffer){ 00129 i++; 00130 } 00131 } 00132 00133 /* Fetch received data as it is received. */ 00134 i = 0; 00135 while (i < NUM_BYTES) { 00136 if (USART_RXBufferData_Available(&USART_data)) { 00137 receiveArray[i] = USART_RXBuffer_GetByte(&USART_data); 00138 i++; 00139 } 00140 } 00141 00142 /* Test to see if sent data equals received data. */ 00143 /* Assume success first.*/ 00144 success = true; 00145 for(i = 0; i < NUM_BYTES; i++) { 00146 /* Check that each element is received correctly. */ 00147 if (receiveArray[i] != sendArray[i]) { 00148 success = false; 00149 } 00150 } 00151 00152 /* If success the program ends up inside the if statement.*/ 00153 if(success){ 00154 while(true); 00155 }else{ 00156 while(true); 00157 } 00158 } Here is the call graph for this function: Variable Documentation uint8_t receiveArray[NUM_BYTES] Array to put received data in. Definition at line 64 of file usart_example_interrupt.c. Referenced by main(). uint8_t sendArray[NUM_BYTES] = {0x55, 0xaa, 0xf0} Test data to send. Definition at line 62 of file usart_example_interrupt.c. Referenced by main(). bool success Success variable, used to test driver. Definition at line 66 of file usart_example_interrupt.c. Referenced by main(). USART_data_t USART_data USART data struct used in example. Definition at line 60 of file usart_example_interrupt.c. @DOC_TITLE@ Generated on Wed Nov 5 10:23:28 2008 for AVRxxxx Application note title by 1.5.5