C2000 - Added timer based interrupt driver

hardware/c2000/cores/c2000/Energia.h

@@ -190,6 +190,9 @@ unsigned long pulseIn(uint8_t pin, uint8_t state, unsigned long timeout = 100000
 void tone(uint8_t _pin, unsigned int frequency, unsigned long duration = 0);
 void noTone(uint8_t _pin);
 
+void timer( unsigned int frequency, void (*userFunc)(void));
+void inline stopTimer(void);
+
 // WMath prototypes
 long random(long);
 long random(long, long);

hardware/c2000/cores/c2000/Timer.cpp

@@ -0,0 +1,172 @@
+/*
+  *************************************************************************
+  *	tone.c
+  *
+  *	Energia core files for C2000
+  *		Copyright (c) 2012 Trey German. All right reserved.
+  *
+  *
+  ***********************************************************************
+
+  A Tone Generator Library - Modified for Energia
+  Implements up to 3 (software) PWM outputs using TIMERA0 compare registers and IRQ. 
+  Can use any digital output pin for pulse generation
+ 
+  (c) 2012 - Peter Brier.
+
+  Based on code Originally written by Brett Hagman
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+Version Modified By Date     Comments
+------- ----------- -------- --------
+0001    B Hagman    09/08/02 Initial coding
+0002    B Hagman    09/08/18 Multiple pins
+0003    B Hagman    09/08/18 Moved initialization from constructor to begin()
+0004    B Hagman    09/09/26 Fixed problems with ATmega8
+0005    B Hagman    09/11/23 Scanned prescalars for best fit on 8 bit timers
+                    09/11/25 Changed pin toggle method to XOR
+                    09/11/25 Fixed timer0 from being excluded
+0006    D Mellis    09/12/29 Replaced objects with functions
+0007    M Sproul    10/08/29 Changed #ifdefs from cpu to register
+0008    P Brier     12/05/28 Modified for TI MSP430 processor
+0009    P Brier     12/05/29 Fixed problem with re-init of expired tone
+*************************************************/
+
+#include "wiring_private.h"
+#include "pins_energia.h"
+#include "Energia.h"
+
+// local funcions
+static void initTimers();
+static void setTimer(unsigned int frequency, void (*userFunc)(void));
+ void stopTimer(uint8_t n);
+interrupt void cpu_timer0_isr(void);
+
+// timer clock frequency set to clock/8, at F_CPU = 1MHZ this gives an output freq range of ~[1Hz ..65Khz] and at 16Mhz this is ~[16Hz .. 1MHz]
+#define F_TIMER (F_CPU/60L)
+
+
+#define AVAILABLE_TONE_PINS 2
+#define SETARRAY(a) a,a
+
+
+// tone_duration:
+//  > 0 - duration specified
+//  = 0 - stopped
+//  < 0 - infinitely (until stop() method called, or new play() called)
+
+static uint8_t timer_state = 0; // 0==not initialized, 1==timer running
+//static uint16_t tone_interval[AVAILABLE_TONE_PINS] = { SETARRAY(-1)  };
+//Above line changed to prevent build warnings
+static uint16_t timer_interval = 0; 
+
+static volatile voidFuncPtr intFuncP0;
+
+/**
+*** tone() -- Output a tone (50% Dutycycle PWM signal) on a pin
+***  pin: This pin is selected as output
+***  frequency: [Hertz] 
+**   duration: [milliseconds], if duration <=0, then we output tone continously, otherwise tone is stopped after this time (output = 0)
+**/
+void timer( unsigned int frequency, void (*userFunc)(void))
+{
+
+
+      if ( timer_state == 0 ) 
+        initTimers();
+      setTimer(frequency, userFunc);
+      return; // we are done, timer set
+
+}
+
+
+
+
+
+// Initialize the timers - Set mode and Enable IRQ
+static void inline initTimers()
+{
+   EALLOW;  // This is needed to write to EALLOW protected registers
+   PieVectTable.TINT0 = &cpu_timer0_isr;
+   PieCtrlRegs.PIEIER1.bit.INTx7 = 1;
+   IER |= M_INT1;
+   EDIS;    // This is needed to disable write to EALLOW protected registers
+
+
+	CpuTimer0Regs.TPR.all  = 0;
+	CpuTimer0Regs.TPRH.all = 0;
+	CpuTimer0Regs.TCR.bit.TSS = 1;
+	CpuTimer0Regs.TCR.bit.TIE = 0;
+	//divide by 60 to get 1MHz timer
+	CpuTimer0Regs.TPR.bit.TDDR = 59;
+
+
+  timer_state = 1;  // init is done
+}
+
+
+// Set the timer interval and duration
+// frequency in [Hz] and duration in [msec]
+// we initialize the timer match value only if the tone was not running already, to prevent glitches when re-programming a running tone
+static void setTimer(unsigned int frequency, void (*userFunc)(void))
+{
+  if ( frequency <= 0 ) 
+  {
+    return;
+  }
+
+  timer_interval = F_TIMER / (2L*frequency);
+
+
+  intFuncP0 = userFunc;
+
+  if ( CpuTimer0Regs.TCR.bit.TIE == 0 )
+  {
+   	  CpuTimer0Regs.PRD.all =  timer_interval;
+  }
+  CpuTimer0Regs.TCR.bit.TIE = 1;
+  CpuTimer0Regs.TCR.bit.TSS = 0;
+  EINT;
+
+} 
+
+/* stopTimer() - Disable timer IRQ */
+void inline stopTimer(void)
+{
+
+    CpuTimer0Regs.TCR.bit.TSS = 1;
+    CpuTimer0Regs.TCR.bit.TIE = 0;
+
+
+}
+
+
+// Peform the isr magic, toggle output, decrease duation if > 0, and stop if duration == 0, continous if duration < 0
+// set new interval - defined as macro to limit ISR overhead (at the expense of some code size)
+#define isrTimer(n,ccr) do { \
+  *tone_out[n] ^= tone_bit[n]; \
+  if ( tone_periods[n] == 0 ) stopTimer(n);\
+  else if ( tone_periods[n] > 0) tone_periods[n]--; \
+}while(0)
+
+
+interrupt void cpu_timer0_isr(void)
+{
+    intFuncP0();
+    PieCtrlRegs.PIEACK.bit.ACK1  = 1;
+}
+
+

hardware/c2000/cores/c2000/Tone.cpp

@@ -50,7 +50,7 @@ Version Modified By Date     Comments
 #include "Energia.h"
 
 // local funcions
-static void initTimers();
+static void initToneTimers();
 static void setTimer(uint8_t n, unsigned int frequency, unsigned long duration);
 static void stopTimer(uint8_t n);
 interrupt void cpu_timer1_isr(void);
@@ -109,7 +109,7 @@ void tone(uint8_t _pin, unsigned int frequency, unsigned long duration)
       tone_bit[i] = digitalPinToBitMask(_pin);
       tone_out[i] = portOutputRegister(port);
       if ( tone_state == 0 ) 
-        initTimers();
+        initToneTimers();
       pinMode(_pin, OUTPUT);
       setTimer(i, frequency, duration);
       return; // we are done, timer set
@@ -137,7 +137,7 @@ void noTone(uint8_t _pin)
 
 
 // Initialize the timers - Set mode and Enable IRQ
-static void inline initTimers()
+static void inline initToneTimers()
 {
    EALLOW;  // This is needed to write to EALLOW protected registers
    PieVectTable.TINT1 = &cpu_timer1_isr;