X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=cpu%2Favr%2Fdrv%2Fser_simple_avr.c;fp=cpu%2Favr%2Fdrv%2Fser_simple_avr.c;h=7805892a9912769604962e288c271ccac2f1f521;hb=45e52e1aceabd6e40b3c6e301440ad60c1cba29d;hp=0000000000000000000000000000000000000000;hpb=187d609e26aacfd7073ddaa5a9c761c5e9a30765;p=bertos.git diff --git a/cpu/avr/drv/ser_simple_avr.c b/cpu/avr/drv/ser_simple_avr.c new file mode 100644 index 00000000..7805892a --- /dev/null +++ b/cpu/avr/drv/ser_simple_avr.c @@ -0,0 +1,194 @@ +/** + * \file + * + * + * \brief Simple serial I/O driver + * + * \version $Id$ + * \author Francesco Sacchi + */ + +/*#* + *#* $Log$ + *#* Revision 1.2 2006/07/19 12:56:26 bernie + *#* Convert to new Doxygen style. + *#* + *#* Revision 1.1 2005/04/12 01:37:50 bernie + *#* Import into DevLib. + *#* + *#* Revision 1.7 2005/01/23 12:24:27 bernie + *#* Include macros.h for BV(). + *#* + *#* Revision 1.6 2004/10/20 13:40:54 batt + *#* Put {} instead of ; after while loop. + *#* + *#* Revision 1.5 2004/10/20 13:39:40 batt + *#* Reformat. + *#* + *#* Revision 1.4 2004/10/20 13:30:02 batt + *#* Optimization of UCSR0C writing + *#* + *#* Revision 1.3 2004/10/14 15:55:32 batt + *#* Add ser_purge. + *#* + *#* Revision 1.2 2004/10/14 14:46:59 batt + *#* Change baudrate calculation. + *#* + *#* Revision 1.1 2004/10/13 16:35:36 batt + *#* New (simple) serial driver. + *#*/ +#include "ser_simple.h" + +#include +#include +#include /* BV() */ +#include + +#include + +/** + * Send a character over the serial line. + * + * \return the character sent. + */ +int _ser_putchar(int c) +{ + /* Disable Rx to avoid echo*/ + UCSR0B &= ~BV(RXEN); + /* Enable tx*/ + UCSR0B |= BV(TXEN); + /* Prepare transmission */ + UDR0 = c; + /* Wait until byte sent */ + while (!(UCSR0A & BV(TXC))) {} + /* Disable tx to avoid short circuit when tx and rx share the same wire. */ + UCSR0B &= ~BV(TXEN); + /* Enable Rx */ + UCSR0B |= BV(RXEN); + /* Delete TRANSMIT_COMPLETE_BIT flag */ + UCSR0A |= BV(TXC); + return c; +} + + +/** + * Get a character from the serial line. + * If ther is no character in the buffer this function wait until + * one is received (no timeout). + * + * \return the character received. + */ +int _ser_getchar(void) +{ + /* Wait for data */ + while (!(UCSR0A & BV(RXC))) {} + return UDR0; + +} + + +/** + * Get a character from the receiver buffer + * If the buffer is empty, ser_getchar_nowait() returns + * immediatly EOF. + */ +int _ser_getchar_nowait(void) +{ + if (!(UCSR0A & BV(RXC))) return EOF; + else return UDR0; +} + +void _ser_settimeouts(void) +{ +} + +/** + * Set the baudrate. + */ +void _ser_setbaudrate(unsigned long rate) +{ + /* Compute baud-rate period */ + uint16_t period = (((CLOCK_FREQ / 16UL) + (rate / 2)) / rate) - 1; + + UBRR0H = (period) >> 8; + UBRR0L = (period); +} + +/** + * Send a string. + */ +int _ser_print(const char *s) +{ + while(*s) _ser_putchar(*s++); + return 0; +} + + +void _ser_setparity(int parity) +{ + /* Set the new parity */ + UCSR0C |= (UCSR0C & ~(BV(UPM1) | BV(UPM0))) | (parity << UPM0); +} + +/** + * Dummy functions. + */ +void _ser_purge(void) +{ + while (_ser_getchar_nowait() != EOF) {} +} + +/** + * Initialize serial. + */ +struct Serial * _ser_open(void) +{ + /* + * Set Rx and Tx pins as input to avoid short + * circuit when serial is disabled. + */ + DDRE &= ~(BV(PE0)|BV(PE1)); + PORTE &= ~BV(PE0); + PORTE |= BV(PE1); + /* Enable only Rx section */ + UCSR0B = BV(RXEN); + return NULL; +} + + +/** + * Clean up serial port, disabling the associated hardware. + */ +void _ser_close(void) +{ + /* Disable Rx & Tx. */ + UCSR0B &= ~(BV(RXEN) | BV(TXEN)); +}