/* Copyright (c) 2002, 2004 Marek Michalkiewicz Copyright (c) 2005, 2006, 2007 Eric B. Weddington All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * 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. * Neither the name of the copyright holders nor the names of contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS 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. */ /* $Id$ */ /* avr/wdt.h - macros for AVR watchdog timer */ #ifndef _AVR_WDT_H_ #define _AVR_WDT_H_ #include #include /** \file */ /** \defgroup avr_watchdog : Watchdog timer handling \code #include \endcode This header file declares the interface to some inline macros handling the watchdog timer present in many AVR devices. In order to prevent the watchdog timer configuration from being accidentally altered by a crashing application, a special timed sequence is required in order to change it. The macros within this header file handle the required sequence automatically before changing any value. Interrupts will be disabled during the manipulation. \note Depending on the fuse configuration of the particular device, further restrictions might apply, in particular it might be disallowed to turn off the watchdog timer. Note that for newer devices (ATmega88 and newer, effectively any AVR that has the option to also generate interrupts), the watchdog timer remains active even after a system reset (except a power-on condition), using the fastest prescaler value (approximately 15 ms). It is therefore required to turn off the watchdog early during program startup, the datasheet recommends a sequence like the following: \code #include #include uint8_t mcusr_mirror __attribute__ ((section (".noinit"))); void get_mcusr(void) \ __attribute__((naked)) \ __attribute__((section(".init3"))); void get_mcusr(void) { mcusr_mirror = MCUSR; MCUSR = 0; wdt_disable(); } \endcode Saving the value of MCUSR in \c mcusr_mirror is only needed if the application later wants to examine the reset source, but in particular, clearing the watchdog reset flag before disabling the watchdog is required, according to the datasheet. */ /** \ingroup avr_watchdog Reset the watchdog timer. When the watchdog timer is enabled, a call to this instruction is required before the timer expires, otherwise a watchdog-initiated device reset will occur. */ #define wdt_reset() __asm__ __volatile__ ("wdr") #if defined(WDP3) # define _WD_PS3_MASK _BV(WDP3) #else # define _WD_PS3_MASK 0x00 #endif #if defined(WDTCSR) # define _WD_CONTROL_REG WDTCSR #else # define _WD_CONTROL_REG WDTCR #endif #if defined(WDTOE) #define _WD_CHANGE_BIT WDTOE #else #define _WD_CHANGE_BIT WDCE #endif /** \ingroup avr_watchdog Enable the watchdog timer, configuring it for expiry after \c timeout (which is a combination of the \c WDP0 through \c WDP2 bits to write into the \c WDTCR register; For those devices that have a \c WDTCSR register, it uses the combination of the \c WDP0 through \c WDP3 bits). See also the symbolic constants \c WDTO_15MS et al. */ #if defined(__AVR_ATxmega16A4__) \ || defined(__AVR_ATxmega16D4__) \ || defined(__AVR_ATxmega32A4__) \ || defined(__AVR_ATxmega32D4__) \ || defined(__AVR_ATxmega64A1__) \ || defined(__AVR_ATxmega64A3__) \ || defined(__AVR_ATxmega128A1__) \ || defined(__AVR_ATxmega128A3__) \ || defined(__AVR_ATxmega256A3__) \ || defined(__AVR_ATxmega256A3B__) /* wdt_enable(WDT_PER_8KCLK_gc); */ #define wdt_enable(value) \ __asm__ __volatile__ ( \ "in __tmp_reg__, %0" "\n\t" \ "out %1, %3" "\n\t" \ "sts %2, %4" "\n\t" \ "wdr" "\n\t" \ "out %0, __tmp_reg__" "\n\t" \ : \ : "M" (_SFR_MEM_ADDR(RAMPD)), \ "M" (_SFR_MEM_ADDR(CCP)), \ "M" (_SFR_MEM_ADDR(WDT_CTRL)), \ "r" ((uint8_t)0xD8), \ "r" ((uint8_t)(WDT_CEN_bm | WDT_ENABLE_bm | value)) \ : "r0" \ ) #elif defined(__AVR_AT90CAN32__) \ || defined(__AVR_AT90CAN64__) \ || defined(__AVR_AT90CAN128__) \ || defined(__AVR_AT90PWM1__) \ || defined(__AVR_AT90PWM2__) \ || defined(__AVR_AT90PWM216__) \ || defined(__AVR_AT90PWM2B__) \ || defined(__AVR_AT90PWM3__) \ || defined(__AVR_AT90PWM316__) \ || defined(__AVR_AT90PWM3B__) \ || defined(__AVR_AT90PWM81__) \ || defined(__AVR_AT90USB1286__) \ || defined(__AVR_AT90USB1287__) \ || defined(__AVR_AT90USB162__) \ || defined(__AVR_AT90USB646__) \ || defined(__AVR_AT90USB647__) \ || defined(__AVR_AT90USB82__) \ || defined(__AVR_ATmega1280__) \ || defined(__AVR_ATmega1281__) \ || defined(__AVR_ATmega1284P__) \ || defined(__AVR_ATmega128RFA1__) \ || defined(__AVR_ATmega164__) \ || defined(__AVR_ATmega164P__) \ || defined(__AVR_ATmega165__) \ || defined(__AVR_ATmega165P__) \ || defined(__AVR_ATmega168__) \ || defined(__AVR_ATmega168P__) \ || defined(__AVR_ATmega169__) \ || defined(__AVR_ATmega169P__) \ || defined(__AVR_ATmega16HVA__) \ || defined(__AVR_ATmega16M1__) \ || defined(__AVR_ATmega16U4__) \ || defined(__AVR_ATmega2560__) \ || defined(__AVR_ATmega2561__) \ || defined(__AVR_ATmega324__) \ || defined(__AVR_ATmega324P__) \ || defined(__AVR_ATmega325__) \ || defined(__AVR_ATmega3250__) \ || defined(__AVR_ATmega328P__) \ || defined(__AVR_ATmega329__) \ || defined(__AVR_ATmega329P__) \ || defined(__AVR_ATmega3290__) \ || defined(__AVR_ATmega3290P__) \ || defined(__AVR_ATmega32C1__) \ || defined(__AVR_ATmega32HVB__) \ || defined(__AVR_ATmega32M1__) \ || defined(__AVR_ATmega32U4__) \ || defined(__AVR_ATmega32U6__) \ || defined(__AVR_ATmega406__) \ || defined(__AVR_ATmega48__) \ || defined(__AVR_ATmega48P__) \ || defined(__AVR_ATmega640__) \ || defined(__AVR_ATmega644__) \ || defined(__AVR_ATmega644P__) \ || defined(__AVR_ATmega645__) \ || defined(__AVR_ATmega6450__) \ || defined(__AVR_ATmega649__) \ || defined(__AVR_ATmega6490__) \ || defined(__AVR_ATmega64C1__) \ || defined(__AVR_ATmega64M1__) \ || defined(__AVR_ATmega8HVA__) \ || defined(__AVR_ATmega88__) \ || defined(__AVR_ATmega88P__) \ || defined(__AVR_ATtiny48__) \ || defined(__AVR_ATtiny88__) \ || defined(__AVR_ATtiny87__) \ || defined(__AVR_ATtiny167__) \ || defined(__AVR_AT90SCR100__) \ || defined(__AVR_ATA6289__) /* Use STS instruction. */ #define wdt_enable(value) \ __asm__ __volatile__ ( \ "in __tmp_reg__,__SREG__" "\n\t" \ "cli" "\n\t" \ "wdr" "\n\t" \ "sts %0,%1" "\n\t" \ "out __SREG__,__tmp_reg__" "\n\t" \ "sts %0,%2" "\n\t" \ : /* no outputs */ \ : "M" (_SFR_MEM_ADDR(_WD_CONTROL_REG)), \ "r" (_BV(_WD_CHANGE_BIT) | _BV(WDE)), \ "r" ((uint8_t) ((value & 0x08 ? _WD_PS3_MASK : 0x00) | \ _BV(WDE) | (value & 0x07)) ) \ : "r0" \ ) #define wdt_disable() \ __asm__ __volatile__ ( \ "in __tmp_reg__, __SREG__" "\n\t" \ "cli" "\n\t" \ "sts %0, %1" "\n\t" \ "sts %0, __zero_reg__" "\n\t" \ "out __SREG__,__tmp_reg__" "\n\t" \ : /* no outputs */ \ : "M" (_SFR_MEM_ADDR(_WD_CONTROL_REG)), \ "r" ((uint8_t)(_BV(_WD_CHANGE_BIT) | _BV(WDE))) \ : "r0" \ ) #else /* Use OUT instruction. */ #define wdt_enable(value) \ __asm__ __volatile__ ( \ "in __tmp_reg__,__SREG__" "\n\t" \ "cli" "\n\t" \ "wdr" "\n\t" \ "out %0,%1" "\n\t" \ "out __SREG__,__tmp_reg__" "\n\t" \ "out %0,%2" \ : /* no outputs */ \ : "I" (_SFR_IO_ADDR(_WD_CONTROL_REG)), \ "r" (_BV(_WD_CHANGE_BIT) | _BV(WDE)), \ "r" ((uint8_t) ((value & 0x08 ? _WD_PS3_MASK : 0x00) | \ _BV(WDE) | (value & 0x07)) ) \ : "r0" \ ) /** \ingroup avr_watchdog Disable the watchdog timer, if possible. This attempts to turn off the Enable bit in the watchdog control register. See the datasheet for details. */ #define wdt_disable() \ __asm__ __volatile__ ( \ "in __tmp_reg__, __SREG__" "\n\t" \ "cli" "\n\t" \ "out %0, %1" "\n\t" \ "out %0, __zero_reg__" "\n\t" \ "out __SREG__,__tmp_reg__" "\n\t" \ : /* no outputs */ \ : "I" (_SFR_IO_ADDR(_WD_CONTROL_REG)), \ "r" ((uint8_t)(_BV(_WD_CHANGE_BIT) | _BV(WDE))) \ : "r0" \ ) #endif /** \ingroup avr_watchdog Symbolic constants for the watchdog timeout. Since the watchdog timer is based on a free-running RC oscillator, the times are approximate only and apply to a supply voltage of 5 V. At lower supply voltages, the times will increase. For older devices, the times will be as large as three times when operating at Vcc = 3 V, while the newer devices (e. g. ATmega128, ATmega8) only experience a negligible change. Possible timeout values are: 15 ms, 30 ms, 60 ms, 120 ms, 250 ms, 500 ms, 1 s, 2 s. (Some devices also allow for 4 s and 8 s.) Symbolic constants are formed by the prefix \c WDTO_, followed by the time. Example that would select a watchdog timer expiry of approximately 500 ms: \code wdt_enable(WDTO_500MS); \endcode */ #define WDTO_15MS 0 /** \ingroup avr_watchdog See \c WDT0_15MS */ #define WDTO_30MS 1 /** \ingroup avr_watchdog See \c WDT0_15MS */ #define WDTO_60MS 2 /** \ingroup avr_watchdog See \c WDT0_15MS */ #define WDTO_120MS 3 /** \ingroup avr_watchdog See \c WDT0_15MS */ #define WDTO_250MS 4 /** \ingroup avr_watchdog See \c WDT0_15MS */ #define WDTO_500MS 5 /** \ingroup avr_watchdog See \c WDT0_15MS */ #define WDTO_1S 6 /** \ingroup avr_watchdog See \c WDT0_15MS */ #define WDTO_2S 7 #if defined(__DOXYGEN__) || defined(WDP3) /** \ingroup avr_watchdog See \c WDT0_15MS Note: This is only available on the ATtiny2313, ATtiny24, ATtiny44, ATtiny84, ATtiny25, ATtiny45, ATtiny85, ATtiny261, ATtiny461, ATtiny861, ATmega48, ATmega88, ATmega168, ATmega48P, ATmega88P, ATmega168P, ATmega328P, ATmega164P, ATmega324P, ATmega644P, ATmega644, ATmega640, ATmega1280, ATmega1281, ATmega2560, ATmega2561, ATmega8HVA, ATmega16HVA, ATmega32HVB, ATmega406, ATmega1284P, AT90PWM1, AT90PWM2, AT90PWM2B, AT90PWM3, AT90PWM3B, AT90PWM216, AT90PWM316, AT90PWM81, AT90USB82, AT90USB162, AT90USB646, AT90USB647, AT90USB1286, AT90USB1287, ATtiny48, ATtiny88. */ #define WDTO_4S 8 /** \ingroup avr_watchdog See \c WDT0_15MS Note: This is only available on the ATtiny2313, ATtiny24, ATtiny44, ATtiny84, ATtiny25, ATtiny45, ATtiny85, ATtiny261, ATtiny461, ATtiny861, ATmega48, ATmega88, ATmega168, ATmega48P, ATmega88P, ATmega168P, ATmega328P, ATmega164P, ATmega324P, ATmega644P, ATmega644, ATmega640, ATmega1280, ATmega1281, ATmega2560, ATmega2561, ATmega8HVA, ATmega16HVA, ATmega32HVB, ATmega406, ATmega1284P, AT90PWM1, AT90PWM2, AT90PWM2B, AT90PWM3, AT90PWM3B, AT90PWM216, AT90PWM316, AT90PWM81, AT90USB82, AT90USB162, AT90USB646, AT90USB647, AT90USB1286, AT90USB1287, ATtiny48, ATtiny88. */ #define WDTO_8S 9 #endif /* defined(__DOXYGEN__) || defined(WDP3) */ #endif /* _AVR_WDT_H_ */