usart.h File Reference

Detailed Description

MMU example application.

This file gives an example of using the MMU to manage the memory on AVR32 MCUs.

Author:
Atmel Corporation: http://www.atmel.com
Support email: avr32@atmel.com
$Name$
Revision
$RCSfile$
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Definition in file usart.h.

#include <avr32/io.h>
#include <stdio.h>
#include "settings.h"

Include dependency graph for usart.h:

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Data Structures

struct  usart_options_t
 Input parameters when initializing rs232 mode. More...

Defines

#define USART_1_5_STOPBITS   1
 Use 1.5 stop bits.
#define USART_1_STOPBIT   0
 Use 1 stop bit.
#define USART_2_STOPBITS   2
 Use 2 stop bits (for more, just give the number of bits).
#define USART_ADDR_RECEIVED   1
 Value returned by receiver function when an address character was received.
#define USART_AUTO_ECHO   1
 Set usart channel to echo data.
#define USART_DEFAULT_TIMEOUT   10000
 Default timeout value; number of tries before timing out.
#define USART_ERROR_ARGUMENT   1
 Value returned by function when the input paramters are out of range.
#define USART_EVEN_PARITY   0
 Use even parity on character transmission.
#define USART_FAILURE   -1
 Value returned by function when it was unable to complete successfully for some unspecified reason.
#define USART_LOCAL_LOOPBACK   2
 Set usart channel to local loopback.
#define USART_MARK_PARITY   3
 Use a mark as parity bit.
#define USART_MODE_FAULT   5
 Value returned by a function when the usart is not in the appropriate mode.
#define USART_MODE_HW_HSH   0x02
 Operate usart in rs232 with hardware handshaking.
#define USART_MODE_IRDA   0x08
 Oparte usart in irda mode.
#define USART_MODE_ISO7816_T0   0x04
 Operate usart in iso7816, T=0 mode.
#define USART_MODE_ISO7816_T1   0x06
 Operate usart in iso7816, T=1 mode.
#define USART_MODE_MODEM   0x03
 Operate usart in modem mode.
#define USART_MODE_NORMAL   0x00
 Operate usart in normal rs232 mode.
#define USART_MODE_RS485   0x01
 Operate usart in rs485 mode.
#define USART_MODE_SW_HSH   0x0C
 Operate usart in rs232 with software handshaking.
#define USART_MULTIDROP_PARITY   6
 Parity bit is used to flag address characters.
#define USART_NO_PARITY   4
 Don't use a parity bit.
#define USART_NORMAL_CHMODE   0
 Set usart channel to normal communcation.
#define USART_ODD_PARITY   1
 Use odd parity on character transmission.
#define USART_OK   0
 Value returned by function when it completed successfully.
#define USART_REMOTE_LOOPBACK   3
 Set usart channel to remote loopback.
#define USART_RX_EMPTY   3
 Value returned by receiver function when nothing was received.
#define USART_RX_ERROR   4
 Value returned by receiver function when transmission error occured.
#define USART_SPACE_PARITY   2
 Use a space as parity bit.
#define USART_TX_BUSY   2
 Value returned by transmission function when transmitter was busy.

Functions

int _write_r (struct _reent *ptr, int fd, const void *buf, size_t cnt)
 Function to overload the standard _write_r, makes it possible to use printf() to output data.
int usart_linit (volatile avr32_usart_t *usart, const struct usart_options_t *opt, const long cpuHz)
 Setup the usart to use the standard RS232 protocol.
int usart_putchar (volatile avr32_usart_t *usart, const short character)
 Send a character with the usart.
void usart_reset (volatile avr32_usart_t *usart)
 This function will reset the USART, and disable TX and RX.

Define Documentation

#define USART_1_5_STOPBITS   1

Use 1.5 stop bits.

Definition at line 126 of file usart.h.

#define USART_1_STOPBIT   0

Use 1 stop bit.

Definition at line 124 of file usart.h.

Referenced by main().

#define USART_2_STOPBITS   2

Use 2 stop bits (for more, just give the number of bits).

Definition at line 128 of file usart.h.

#define USART_ADDR_RECEIVED   1

Value returned by receiver function when an address character was received.

Definition at line 79 of file usart.h.

#define USART_AUTO_ECHO   1

Set usart channel to echo data.

Definition at line 117 of file usart.h.

#define USART_DEFAULT_TIMEOUT   10000

Default timeout value; number of tries before timing out.

Definition at line 82 of file usart.h.

Referenced by usart_putchar().

#define USART_ERROR_ARGUMENT   1

Value returned by function when the input paramters are out of range.

Definition at line 65 of file usart.h.

Referenced by usart_linit(), and usart_set_baudrate().

#define USART_EVEN_PARITY   0

Use even parity on character transmission.

Definition at line 85 of file usart.h.

#define USART_FAILURE   -1

Value returned by function when it was unable to complete successfully for some unspecified reason.

Definition at line 62 of file usart.h.

#define USART_LOCAL_LOOPBACK   2

Set usart channel to local loopback.

Definition at line 119 of file usart.h.

#define USART_MARK_PARITY   3

Use a mark as parity bit.

Definition at line 91 of file usart.h.

#define USART_MODE_FAULT   5

Value returned by a function when the usart is not in the appropriate mode.

Definition at line 75 of file usart.h.

#define USART_MODE_HW_HSH   0x02

Operate usart in rs232 with hardware handshaking.

Definition at line 102 of file usart.h.

#define USART_MODE_IRDA   0x08

Oparte usart in irda mode.

Definition at line 110 of file usart.h.

#define USART_MODE_ISO7816_T0   0x04

Operate usart in iso7816, T=0 mode.

Definition at line 106 of file usart.h.

#define USART_MODE_ISO7816_T1   0x06

Operate usart in iso7816, T=1 mode.

Definition at line 108 of file usart.h.

#define USART_MODE_MODEM   0x03

Operate usart in modem mode.

Definition at line 104 of file usart.h.

#define USART_MODE_NORMAL   0x00

Operate usart in normal rs232 mode.

Definition at line 98 of file usart.h.

#define USART_MODE_RS485   0x01

Operate usart in rs485 mode.

Definition at line 100 of file usart.h.

#define USART_MODE_SW_HSH   0x0C

Operate usart in rs232 with software handshaking.

Definition at line 112 of file usart.h.

#define USART_MULTIDROP_PARITY   6

Parity bit is used to flag address characters.

Definition at line 95 of file usart.h.

#define USART_NO_PARITY   4

Don't use a parity bit.

Definition at line 93 of file usart.h.

Referenced by main().

#define USART_NORMAL_CHMODE   0

Set usart channel to normal communcation.

Definition at line 115 of file usart.h.

Referenced by main().

#define USART_ODD_PARITY   1

Use odd parity on character transmission.

Definition at line 87 of file usart.h.

#define USART_OK   0

Value returned by function when it completed successfully.

Definition at line 58 of file usart.h.

Referenced by main(), usart_linit(), usart_putchar(), and usart_set_baudrate().

#define USART_REMOTE_LOOPBACK   3

Set usart channel to remote loopback.

Definition at line 121 of file usart.h.

#define USART_RX_EMPTY   3

Value returned by receiver function when nothing was received.

Definition at line 69 of file usart.h.

#define USART_RX_ERROR   4

Value returned by receiver function when transmission error occured.

Definition at line 71 of file usart.h.

#define USART_SPACE_PARITY   2

Use a space as parity bit.

Definition at line 89 of file usart.h.

#define USART_TX_BUSY   2

Value returned by transmission function when transmitter was busy.

Definition at line 67 of file usart.h.

Referenced by usart_putchar().

Function Documentation

int _write_r ( struct _reent *  ptr,
int  fd,
const void *  buf,
size_t  cnt 
)

Function to overload the standard _write_r, makes it possible to use printf() to output data.

Parameters:
ptr not used
fd not used
buf the buffer to send
cnt number of bytes to send
Returns:
Status

Definition at line 252 of file usart.c.

References USART_MODULE, and usart_putchar().

00253 {
00254     volatile char *msg = (char *) buf;
00255     volatile int i;
00256 
00257     for (i=0; i < cnt; i++) {
00258         usart_putchar(&USART_MODULE, *msg++);
00259     }
00260 
00261     return cnt;
00262 }

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int usart_linit ( volatile avr32_usart_t *  usart,
const struct usart_options_t *  opt,
const long  cpuHz 
)

Setup the usart to use the standard RS232 protocol.

Parameters:
usart base address of the usart
opt options needed to set up RS232 communcation (see usart_options_t)
cpuHz frequency of the selected clock
Returns:
status
Return values:
USART_OK on success
USART_ERROR_ARGUMENT on wrong arguments

Definition at line 152 of file usart.c.

References usart_options_t::baudrate, usart_options_t::channelmode, usart_options_t::charlength, usart_options_t::paritytype, usart_options_t::stopbits, USART_ERROR_ARGUMENT, USART_OK, usart_reset(), and usart_set_baudrate().

00155 {
00156     int retval;
00157 
00158     /* reset the usart and shutdown RX and TX */
00159     usart_reset(usart);
00160 
00161     /* control input values */
00162     if (opt == 0) {
00163         return USART_ERROR_ARGUMENT;
00164     }
00165     if (opt->charlength < 5 || opt->charlength > 9) {
00166         return USART_ERROR_ARGUMENT;
00167     }
00168     if (opt->paritytype > 7) {
00169         return USART_ERROR_ARGUMENT;
00170     }
00171     if (opt->stopbits > 2+255) {
00172         return USART_ERROR_ARGUMENT;
00173     }
00174     if (opt->channelmode > 3) {
00175         return USART_ERROR_ARGUMENT;
00176     }
00177 
00178     retval = usart_set_baudrate(usart, opt->baudrate, cpuHz);
00179 
00180     if (retval != USART_OK) {
00181         return retval;
00182     }
00183 
00184     if (opt->charlength == 9) {
00185         /* charlength set to 9 bits; MODE9 dominates CHRL */
00186         usart->mr |= AVR32_USART_MR_MODE9_MASK;
00187     } else {
00188         /* CHRL gives the charlength(- 5) when USART_MODE9=0 */
00189         usart->mr |=
00190             ((opt->charlength-5)<<AVR32_USART_MR_CHRL_OFFSET);
00191     }
00192 
00193     usart->mr |= (opt->channelmode<<AVR32_USART_MR_CHMODE_OFFSET)|
00194                  (opt->paritytype<<AVR32_USART_MR_PAR_OFFSET);
00195 
00196     if (opt->stopbits > 2) {
00197         /* set two stop bits */
00198         usart->mr |= (2<<AVR32_USART_MR_NBSTOP_OFFSET);
00199         /* and a timeguard period gives the rest */
00200         usart->ttgr = (opt->stopbits-2);
00201     } else {
00202         /* insert 1, 1.5 or 2 stop bits */
00203         usart->mr |= (opt->stopbits<<AVR32_USART_MR_NBSTOP_OFFSET);
00204     }
00205 
00206     /* enable TX and RX */
00207     usart->cr |= AVR32_USART_CR_TXEN_MASK|AVR32_USART_CR_RXEN_MASK;
00208 
00209     return USART_OK;
00210 }

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int usart_putchar ( volatile avr32_usart_t *  usart,
const short  character 
)

Send a character with the usart.

Parameters:
usart base address of the usart
character character to write
Returns:
status
Return values:
USART_OK on success
USART_TX_BUSY on timeout

Definition at line 222 of file usart.c.

References USART_DEFAULT_TIMEOUT, USART_OK, and USART_TX_BUSY.

00223 {
00224     int timeout = USART_DEFAULT_TIMEOUT;
00225 
00226     do {
00227         --timeout;
00228     } while ((usart->csr & AVR32_USART_CSR_TXRDY_MASK) == 0 && timeout > 0);
00229 
00230     if (timeout == 0) {
00231         return USART_TX_BUSY;
00232     }
00233 
00234     usart->thr = character;
00235 
00236     return USART_OK;
00237 }

void usart_reset ( volatile avr32_usart_t *  usart  ) 

This function will reset the USART, and disable TX and RX.

Parameters:
usart Base address of the usart

Definition at line 56 of file usart.c.

00057 {
00058     /* Disable all usart interrupts, interrupts needed should be set
00059        explicitly on every reset */
00060     usart->idr = 0xFFFFffff;
00061 
00062     /* Reset mode and other registers that could cause unpredictable
00063        behaviour after reset */
00064     usart->mr = 0;
00065     usart->rtor = 0;
00066     usart->ttgr = 0;
00067 
00068     /* Shutdown RX and TX (will be reenabled when setup
00069        is completed successfully), reset status bits and turn
00070        off DTR and RTS */
00071     usart->cr = AVR32_USART_CR_RSTRX_MASK|
00072                 AVR32_USART_CR_RSTTX_MASK|
00073                 AVR32_USART_CR_RSTSTA_MASK|
00074                 AVR32_USART_CR_RSTIT_MASK|
00075                 AVR32_USART_CR_RSTNACK_MASK|
00076                 AVR32_USART_CR_DTRDIS_MASK|
00077                 AVR32_USART_CR_RTSDIS_MASK;
00078 }

Generated on Thu Oct 18 09:30:05 2007 for AVR32113 Configuration and Use of the Memory Management Unit by  doxygen 1.5.3