00001 /*! \file timer128.h \brief System Timer function library for Mega128. */ 00002 //***************************************************************************** 00003 // 00004 // File Name : 'timer128.h' 00005 // Title : System Timer function library for Mega128 00006 // Author : Pascal Stang - Copyright (C) 2000-2003 00007 // Created : 11/22/2000 00008 // Revised : 02/10/2003 00009 // Version : 1.1 00010 // Target MCU : Atmel AVR Series 00011 // Editor Tabs : 4 00012 // 00013 // This code is distributed under the GNU Public License 00014 // which can be found at http://www.gnu.org/licenses/gpl.txt 00015 // 00016 /// \ingroup driver_avr 00017 /// \defgroup timer128 Timer Function Library for ATmega128 (timer128.c) 00018 /// \code #include "timer128.h" \endcode 00019 /// \par Overview 00020 /// This library provides functions for use with the timers internal to the 00021 /// AVR ATmega128. Functions include initialization, set prescaler, 00022 /// calibrated pause function (in milliseconds), attaching and detaching 00023 /// of user functions to interrupts, overflow counters, and PWM. 00024 /// 00025 /// \par About Timers 00026 /// The Atmel AVR-series processors each contain at least one 00027 /// hardware timer/counter. Many of the processors contain 2 or 3 00028 /// timers. Generally speaking, a timer is a hardware counter inside 00029 /// the processor which counts at a rate related to the main CPU clock 00030 /// frequency. Because the counter value increasing (counting up) at 00031 /// a precise rate, we can use it as a timer to create or measure 00032 /// precise delays, schedule events, or generate signals of a certain 00033 /// frequency or pulse-width. 00034 /// \par 00035 /// As an example, the ATmega163 processor has 3 timer/counters. 00036 /// Timer0, Timer1, and Timer2 are 8, 16, and 8 bits wide respectively. 00037 /// This means that they overflow, or roll over back to zero, at a 00038 /// count value of 256 for 8bits or 65536 for 16bits. A prescaler is 00039 /// avaiable for each timer, and the prescaler allows you to pre-divide 00040 /// the main CPU clock rate down to a slower speed before feeding it to 00041 /// the counting input of a timer. For example, if the CPU clock 00042 /// frequency is 3.69MHz, and Timer0's prescaler is set to divide-by-8, 00043 /// then Timer0 will "tic" at 3690000/8 = 461250Hz. Because Timer0 is 00044 /// an 8bit timer, it will count to 256 in just 256/461250Hz = 0.555ms. 00045 /// In fact, when it hits 255, it will overflow and start again at 00046 /// zero. In this case, Timer0 will overflow 461250/256 = 1801.76 00047 /// times per second. 00048 /// \par 00049 /// Timer0 can be used a number of ways simultaneously. First, the 00050 /// value of the timer can be read by accessing the CPU register \c TCNT0. 00051 /// We could, for example, figure out how long it takes to execute a 00052 /// C command by recording the value of \c TCNT0 before and after 00053 /// execution, then subtract (after-before) = time elapsed. Or we can 00054 /// enable the overflow interrupt which goes off every time T0 00055 /// overflows and count out longer delays (multiple overflows), or 00056 /// execute a special periodic function at every overflow. 00057 /// \par 00058 /// The other timers (Timer1 and Timer2) offer all the abilities of 00059 /// Timer0 and many more features. Both T1 and T2 can operate as 00060 /// general-purpose timers, but T1 has special hardware allowing it to 00061 /// generate PWM signals, while T2 is specially designed to help count 00062 /// out real time (like hours, minutes, seconds). See the 00063 /// Timer/Counter section of the processor datasheet for more info. 00064 /// 00065 //***************************************************************************** 00066 //@{ 00067 00068 #ifndef TIMER128_H 00069 #define TIMER128_H 00070 00071 #include "global.h" 00072 00073 // constants/macros/typdefs 00074 00075 // Timer/clock prescaler values and timer overflow rates 00076 // tics = rate at which the timer counts up 00077 // 8bitoverflow = rate at which the timer overflows 8bits (or reaches 256) 00078 // 16bit [overflow] = rate at which the timer overflows 16bits (65536) 00079 // 00080 // overflows can be used to generate periodic interrupts 00081 // 00082 // for 8MHz crystal 00083 // 0 = STOP (Timer not counting) 00084 // 1 = CLOCK tics= 8MHz 8bitoverflow= 31250Hz 16bit= 122.070Hz 00085 // 2 = CLOCK/8 tics= 1MHz 8bitoverflow= 3906.25Hz 16bit= 15.259Hz 00086 // 3 = CLOCK/64 tics= 125kHz 8bitoverflow= 488.28Hz 16bit= 1.907Hz 00087 // 4 = CLOCK/256 tics= 31250Hz 8bitoverflow= 122.07Hz 16bit= 0.477Hz 00088 // 5 = CLOCK/1024 tics= 7812.5Hz 8bitoverflow= 30.52Hz 16bit= 0.119Hz 00089 // 6 = External Clock on T(x) pin (falling edge) 00090 // 7 = External Clock on T(x) pin (rising edge) 00091 00092 // for 4MHz crystal 00093 // 0 = STOP (Timer not counting) 00094 // 1 = CLOCK tics= 4MHz 8bitoverflow= 15625Hz 16bit= 61.035Hz 00095 // 2 = CLOCK/8 tics= 500kHz 8bitoverflow= 1953.125Hz 16bit= 7.629Hz 00096 // 3 = CLOCK/64 tics= 62500Hz 8bitoverflow= 244.141Hz 16bit= 0.954Hz 00097 // 4 = CLOCK/256 tics= 15625Hz 8bitoverflow= 61.035Hz 16bit= 0.238Hz 00098 // 5 = CLOCK/1024 tics= 3906.25Hz 8bitoverflow= 15.259Hz 16bit= 0.060Hz 00099 // 6 = External Clock on T(x) pin (falling edge) 00100 // 7 = External Clock on T(x) pin (rising edge) 00101 00102 // for 3.69MHz crystal 00103 // 0 = STOP (Timer not counting) 00104 // 1 = CLOCK tics= 3.69MHz 8bitoverflow= 14414Hz 16bit= 56.304Hz 00105 // 2 = CLOCK/8 tics= 461250Hz 8bitoverflow= 1801.758Hz 16bit= 7.038Hz 00106 // 3 = CLOCK/64 tics= 57625.25Hz 8bitoverflow= 225.220Hz 16bit= 0.880Hz 00107 // 4 = CLOCK/256 tics= 14414.063Hz 8bitoverflow= 56.305Hz 16bit= 0.220Hz 00108 // 5 = CLOCK/1024 tics= 3603.516Hz 8bitoverflow= 14.076Hz 16bit= 0.055Hz 00109 // 6 = External Clock on T(x) pin (falling edge) 00110 // 7 = External Clock on T(x) pin (rising edge) 00111 00112 // for 32.768KHz crystal on timer 2 (use for real-time clock) 00113 // 0 = STOP 00114 // 1 = CLOCK tics= 32.768kHz 8bitoverflow= 128Hz 00115 // 2 = CLOCK/8 tics= 4096kHz 8bitoverflow= 16Hz 00116 // 3 = CLOCK/64 tics= 512Hz 8bitoverflow= 2Hz 00117 // 4 = CLOCK/256 tics= 128Hz 8bitoverflow= 0.5Hz 00118 // 5 = CLOCK/1024 tics= 32Hz 8bitoverflow= 0.125Hz 00119 00120 #define TIMER_CLK_STOP 0x00 ///< Timer Stopped 00121 #define TIMER_CLK_DIV1 0x01 ///< Timer clocked at F_CPU 00122 #define TIMER_CLK_DIV8 0x02 ///< Timer clocked at F_CPU/8 00123 #define TIMER_CLK_DIV64 0x03 ///< Timer clocked at F_CPU/64 00124 #define TIMER_CLK_DIV256 0x04 ///< Timer clocked at F_CPU/256 00125 #define TIMER_CLK_DIV1024 0x05 ///< Timer clocked at F_CPU/1024 00126 #define TIMER_CLK_T_FALL 0x06 ///< Timer clocked at T falling edge 00127 #define TIMER_CLK_T_RISE 0x07 ///< Timer clocked at T rising edge 00128 #define TIMER_PRESCALE_MASK 0x07 ///< Timer Prescaler Bit-Mask 00129 00130 #define TIMERRTC_CLK_STOP 0x00 ///< RTC Timer Stopped 00131 #define TIMERRTC_CLK_DIV1 0x01 ///< RTC Timer clocked at F_CPU 00132 #define TIMERRTC_CLK_DIV8 0x02 ///< RTC Timer clocked at F_CPU/8 00133 #define TIMERRTC_CLK_DIV32 0x03 ///< RTC Timer clocked at F_CPU/32 00134 #define TIMERRTC_CLK_DIV64 0x04 ///< RTC Timer clocked at F_CPU/64 00135 #define TIMERRTC_CLK_DIV128 0x05 ///< RTC Timer clocked at F_CPU/128 00136 #define TIMERRTC_CLK_DIV256 0x06 ///< RTC Timer clocked at F_CPU/256 00137 #define TIMERRTC_CLK_DIV1024 0x07 ///< RTC Timer clocked at F_CPU/1024 00138 #define TIMERRTC_PRESCALE_MASK 0x07 ///< RTC Timer Prescaler Bit-Mask 00139 00140 // default prescale settings for the timers 00141 // these settings are applied when you call 00142 // timerInit or any of the timer<x>Init 00143 #define TIMER0PRESCALE TIMERRTC_CLK_DIV64 ///< timer 0 prescaler default 00144 #define TIMER1PRESCALE TIMER_CLK_DIV64 ///< timer 1 prescaler default 00145 #define TIMER2PRESCALE TIMER_CLK_DIV8 ///< timer 2 prescaler default 00146 #define TIMER3PRESCALE TIMER_CLK_DIV64 ///< timer 3 prescaler default 00147 00148 // interrupt macros for attaching user functions to timer interrupts 00149 // use these with timerAttach( intNum, function ) 00150 // timer 0 00151 #define TIMER0OVERFLOW_INT 0 00152 #define TIMER0OUTCOMPARE_INT 1 00153 // timer 1 00154 #define TIMER1OVERFLOW_INT 2 00155 #define TIMER1OUTCOMPAREA_INT 3 00156 #define TIMER1OUTCOMPAREB_INT 4 00157 #define TIMER1OUTCOMPAREC_INT 5 00158 #define TIMER1INPUTCAPTURE_INT 6 00159 // timer 2 00160 #define TIMER2OVERFLOW_INT 7 00161 #define TIMER2OUTCOMPARE_INT 8 00162 // timer 3 00163 #define TIMER3OVERFLOW_INT 9 00164 #define TIMER3OUTCOMPAREA_INT 10 00165 #define TIMER3OUTCOMPAREB_INT 11 00166 #define TIMER3OUTCOMPAREC_INT 12 00167 #define TIMER3INPUTCAPTURE_INT 13 00168 00169 #define TIMER_NUM_INTERRUPTS 14 00170 00171 // type of interrupt handler to use for timers 00172 // *do not change unless you know what you're doing 00173 // Value may be SIGNAL or INTERRUPT 00174 #ifndef TIMER_INTERRUPT_HANDLER 00175 #define TIMER_INTERRUPT_HANDLER SIGNAL 00176 #endif 00177 00178 // functions 00179 #define delay delay_us 00180 #define delay_ms timerPause 00181 void delay_us(unsigned short time_us); 00182 00183 // initializes timing system 00184 // runs all timer init functions 00185 // sets all timers to default prescale values #defined in systimer.c 00186 void timerInit(void); 00187 00188 // default initialization routines for each timer 00189 void timer0Init(void); 00190 void timer1Init(void); 00191 void timer2Init(void); 00192 void timer3Init(void); 00193 00194 // Clock prescaler set/get commands for each timer/counter 00195 // For setting the prescaler, you should use one of the #defines 00196 // above like TIMER_CLK_DIVx, where [x] is the division rate 00197 // you want. 00198 // When getting the current prescaler setting, the return value 00199 // will be the [x] division value currently set. 00200 void timer0SetPrescaler(u08 prescale); ///< set timer0 prescaler division index 00201 void timer1SetPrescaler(u08 prescale); ///< set timer1 prescaler division index 00202 void timer2SetPrescaler(u08 prescale); ///< set timer2 prescaler division index 00203 void timer3SetPrescaler(u08 prescale); ///< set timer3 prescaler division index 00204 u16 timer0GetPrescaler(void); ///< get timer0 prescaler division rate 00205 u16 timer1GetPrescaler(void); ///< get timer1 prescaler division rate 00206 u16 timer2GetPrescaler(void); ///< get timer2 prescaler division rate 00207 u16 timer3GetPrescaler(void); ///< get timer3 prescaler division rate 00208 00209 00210 // TimerAttach and Detach commands 00211 // These functions allow the attachment (or detachment) of any user function 00212 // to a timer interrupt. "Attaching" one of your own functions to a timer 00213 // interrupt means that it will be called whenever that interrupt happens. 00214 // Using attach is better than rewriting the actual INTERRUPT() function 00215 // because your code will still work and be compatible if the timer library 00216 // is updated. Also, using Attach allows your code and any predefined timer 00217 // code to work together and at the same time. (ie. "attaching" your own 00218 // function to the timer0 overflow doesn't prevent timerPause from working, 00219 // but rather allows you to share the interrupt.) 00220 // 00221 // timerAttach(TIMER1OVERFLOW_INT, myOverflowFunction); 00222 // timerDetach(TIMER1OVERFLOW_INT) 00223 // 00224 // timerAttach causes the myOverflowFunction() to be attached, and therefore 00225 // execute, whenever an overflow on timer1 occurs. timerDetach removes the 00226 // association and executes no user function when the interrupt occurs. 00227 // myOverflowFunction must be defined with no return value and no arguments: 00228 // 00229 // void myOverflowFunction(void) { ... } 00230 00231 void timerAttach(u08 interruptNum, void (*userFunc)(void) ); 00232 void timerDetach(u08 interruptNum); 00233 00234 00235 // timing commands 00236 // timerPause pauses for the number of milliseconds specified in <pause_ms> 00237 void timerPause(unsigned short pause_ms); 00238 00239 // overflow counters 00240 // to be documented 00241 void timer0ClearOverflowCount(void); 00242 long timer0GetOverflowCount(void); 00243 void timer2ClearOverflowCount(void); 00244 long timer2GetOverflowCount(void); 00245 00246 // PWM initialization and set commands for timerX (where X is either 1 or 3) 00247 // timerXPWMInit() 00248 // configures the timerX hardware for PWM mode on pins OCXA, OCXB, and OCXC. 00249 // bitRes should be 8,9,or 10 for 8,9,or 10bit PWM resolution 00250 // 00251 // timerXPWMOff() 00252 // turns off all timerX PWM output and set timer mode to normal state 00253 // 00254 // timerXPWMAOn(), timerXPWMBOn(), timerXPWMCOn() 00255 // turn on output of PWM signals to OCXA,B,C pins 00256 // NOTE: Until you define the OCXA,B,C pins as outputs, and run 00257 // this "on" command, no PWM output will be output 00258 // 00259 // timerXPWMAOff(), timerXPWMBOff(), timerXPWMCOff() 00260 // turn off output of PWM signals to OCXA,B,C pins 00261 // 00262 // timerXPWMASet(), timer1PWMBSet(), timerXPWMCSet() 00263 // sets the PWM duty cycle for each channel 00264 // NOTE: <pwmDuty> should be in the range 0-255 for 8bit PWM 00265 // <pwmDuty> should be in the range 0-511 for 9bit PWM 00266 // <pwmDuty> should be in the range 0-1023 for 10bit PWM 00267 // NOTE: the PWM frequency can be controlled in increments by setting the 00268 // prescaler for timer1 00269 00270 void timer1PWMInit(u08 bitRes); ///< initialize and set timer1 mode to PWM 00271 void timer1PWMInitICR(u16 topcount);///< initialize and set timer1 mode to PWM with specific top count 00272 void timer1PWMOff(void); ///< turn off all timer1 PWM output and set timer mode to normal 00273 void timer1PWMAOn(void); ///< turn on timer1 Channel A (OC1A) PWM output 00274 void timer1PWMBOn(void); ///< turn on timer1 Channel B (OC1B) PWM output 00275 void timer1PWMCOn(void); ///< turn on timer1 Channel C (OC1C) PWM output 00276 void timer1PWMAOff(void); ///< turn off timer1 Channel A (OC1A) PWM output 00277 void timer1PWMBOff(void); ///< turn off timer1 Channel B (OC1B) PWM output 00278 void timer1PWMCOff(void); ///< turn off timer1 Channel C (OC1C) PWM output 00279 void timer1PWMASet(u16 pwmDuty); ///< set duty of timer1 Channel A (OC1A) PWM output 00280 void timer1PWMBSet(u16 pwmDuty); ///< set duty of timer1 Channel B (OC1B) PWM output 00281 void timer1PWMCSet(u16 pwmDuty); ///< set duty of timer1 Channel C (OC1C) PWM output 00282 00283 void timer3PWMInit(u08 bitRes); ///< initialize and set timer3 mode to PWM 00284 void timer3PWMInitICR(u16 topcount);///< initialize and set timer3 mode to PWM with specific top count 00285 void timer3PWMOff(void); ///< turn off all timer3 PWM output and set timer mode to normal 00286 void timer3PWMAOn(void); ///< turn on timer3 Channel A (OC3A) PWM output 00287 void timer3PWMBOn(void); ///< turn on timer3 Channel B (OC3B) PWM output 00288 void timer3PWMCOn(void); ///< turn on timer3 Channel C (OC3C) PWM output 00289 void timer3PWMAOff(void); ///< turn off timer3 Channel A (OC3A) PWM output 00290 void timer3PWMBOff(void); ///< turn off timer3 Channel B (OC3B) PWM output 00291 void timer3PWMCOff(void); ///< turn off timer3 Channel C (OC3C) PWM output 00292 void timer3PWMASet(u16 pwmDuty); ///< set duty of timer3 Channel A (OC3A) PWM output 00293 void timer3PWMBSet(u16 pwmDuty); ///< set duty of timer3 Channel B (OC3B) PWM output 00294 void timer3PWMCSet(u16 pwmDuty); ///< set duty of timer3 Channel C (OC3C) PWM output 00295 00296 //@} 00297 00298 // Pulse generation commands have been moved to the pulse.c library 00299 00300 #endif