Add F_CPU=0x800000 option with phase lock to external 32768 Hz crystal

Add MCU_CONF_LOW_WEAR option to avoid eeprom writes during development.

cpu/avr/dev/clock.c

@@ -93,6 +93,50 @@ ISR(AVR_OUTPUT_COMPARE_INT)
     scount = 0;
     seconds++;
   }
+
+#if F_CPU == 0x800000 && USE_32K_CRYSTAL
+/* Special routine to phase lock CPU to 32768 watch crystal.
+   We are interrupting 128 times per second.
+   If RTIMER_ARCH_SECOND is a multiple of 128 we can use the residual modulo
+   128 to determine whether the clock is too fast or too slow.
+   E.g. for 8192 the phase should be constant modulo 0x40
+   OSCCAL is started in the lower range at 90, allowed to stabilize, then
+   rapidly raised or lowered based on the phase comparison.
+   It gives less phase noise to do this every tick and doesn't seem to hurt anything.
+*/
+#include "rtimer-arch.h"
+{
+volatile static uint8_t lockcount;
+volatile static int16_t last_phase;
+volatile static uint8_t osccalhigh,osccallow;
+    if (seconds < 60) { //give a minute to stabilize
+      if(++lockcount >= 8192UL*128/RTIMER_ARCH_SECOND) {
+        lockcount=0;
+        rtimer_phase = TCNT3 & 0x0fff;
+        if (seconds < 2) OSCCAL=100;
+        if (last_phase > rtimer_phase) osccalhigh=++OSCCAL; else osccallow=--OSCCAL;
+        last_phase = rtimer_phase;
+      }
+    } else {
+#if TICK_MODULO
+    static uint8_t lock_clock;
+    if (++lock_clock>=TICK_MODULO) {
+      lock_clock=0;
+#endif
+      uint8_t error = (TCNT3 - last_phase) & 0x3f;
+      if (error == 0) {
+      } else if (error<32) {
+        OSCCAL=osccallow-1;
+      } else {
+        OSCCAL=osccalhigh+1;
+      }
+#if TICK_MODULO
+    }
+#endif
+    }
+}
+#endif
+
 #if RADIO_CONF_CALIBRATE_INTERVAL
    if (++calibrate_interval==0) {
     rf230_calibrate=1;
@@ -198,6 +242,7 @@ clock_seconds(void)
 }
 #ifdef HANDLE_UNSUPPORTED_INTERRUPTS
 /* Ignore unsupported interrupts, optionally hang for debugging */
+/* BADISR is a gcc weak symbol that matches any undefined interrupt */
 ISR(BADISR_vect) {
 //static volatile uint8_t x;while (1) x++;
 }

cpu/avr/dev/rs232_atmega1284.h

@@ -86,9 +86,23 @@
 #define USART_BAUD_230400 1
 #define USART_BAUD_250000 1
 #define USART_BAUD_500000 0
+#elif F_CPU == 0x800000UL
+/* 8192 KHz with external 32768 crystal */
+#define USART_BAUD_38400 12
+#define USART_BAUD_57600 8
+#define USART_BAUD_115200 4
 #else
-#error "Please define the baud rates for your CPU clock: ATmega128 handbook p. \
-195-198 or set the rate in contiki-conf.h"
+/* UBRR = F_CPU/(16*BAUD) - 1 */
+#warning "Unusual CPU Clock Rate!!!!"
+#warning "You may have to tune the UBRR regisgers for the correct baud rates"
+#warning "See ATmega128 handbook p. 195-198 or set the rate in contiki-conf.h"
+#ifndef USART_BAUD_38400
+#define USART_BAUD_38400 F_CPU/(16*38400) - 1
+#endif
+#ifndef USART_BAUD_57600
+#define USART_BAUD_57600 F_CPU/(16*57600) - 1
+#endif
+
 #endif
 
 

cpu/avr/radio/rf230bb/hal.h

@@ -402,6 +402,10 @@
     #define HAL_TCCR1B_CONFIG ( ( 1 << ICES1 ) | ( 1 << CS12 ) )
     #define HAL_US_PER_SYMBOL ( 1 )
     #define HAL_SYMBOL_MASK   ( 0xFFFFffff )
+#elif ( F_CPU == 0x800000UL )
+    #define HAL_TCCR1B_CONFIG ( ( 1 << ICES1 ) | ( 1 << CS11 ) | ( 1 << CS10 ) )
+    #define HAL_US_PER_SYMBOL ( 2 )
+    #define HAL_SYMBOL_MASK   ( 0x7FFFffff )
 #elif ( F_CPU == 8000000UL )
     #define HAL_TCCR1B_CONFIG ( ( 1 << ICES1 ) | ( 1 << CS11 ) | ( 1 << CS10 ) )
     #define HAL_US_PER_SYMBOL ( 2 )

cpu/avr/rtimer-arch.h

@@ -28,7 +28,6 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: rtimer-arch.h,v 1.5 2010/02/18 17:21:44 dak664 Exp $
  */
 
 #ifndef __RTIMER_ARCH_H__
@@ -42,6 +41,13 @@
  * Setting RTIMER_ARCH_PRESCALER to 0 will leave Timers alone.
  * rtimer_arch_now() will then return 0, likely hanging the cpu if used.
  * Timer1 is used if Timer3 is not available.
+ *
+ * Note the rtimer tick to clock tick conversion will be nominally correct only
+ * when the same oscillator is used for both clocks.
+ * When an external 32768 watch crystal is used for clock ticks my raven CPU
+ * oscillator is 1% slow, 32768 counts on crystal = ~7738 rtimer ticks.
+ * For more accuracy define F_CPU to 0x800000 and optionally phase lock CPU
+ * clock to 32768 crystal. This gives RTIMER_ARCH_SECOND = 8192.
  */
 #ifndef RTIMER_ARCH_PRESCALER
 #define RTIMER_ARCH_PRESCALER 1024UL

platform/avr-raven/contiki-conf.h

@@ -49,6 +49,11 @@
 #ifndef F_CPU
 #define F_CPU          8000000UL
 #endif
+
+/* MCU_CONF_LOW_WEAR will remove the signature and eeprom from the .elf file */
+/* This reduces reprogramming wear during development */
+#define MCU_CONF_LOW_WEAR 0
+
 #include <stdint.h>
 
 typedef int32_t s32_t;
@@ -76,6 +81,7 @@ unsigned long clock_seconds(void);
 
 /* The 1284p can use TIMER2 with the external 32768Hz crystal to keep time. Else TIMER0 is used. */
 /* The sleep timer in raven-lcd.c also uses the crystal and adds a TIMER2 interrupt routine if not already define by clock.c */
+/* If F_CPU is 0x800000 the clock tick interrupt routine will (attempt to) keep the cpu clock phase locked to the crystal. */
 #define AVR_CONF_USE32KCRYSTAL 1
 
 /* Rtimer is implemented through the 16 bit Timer1, clocked at F_CPU through a 1024 prescaler. */

platform/avr-raven/contiki-raven-main.c

@@ -65,7 +65,6 @@ unsigned char debugflowsize,debugflow[DEBUGFLOWSIZE];
 #include "loader/symbols-def.h"
 #include "loader/symtab.h"
 
-#include "params.h"
 #if RF230BB        //radio driver using contiki core mac
 #include "radio/rf230bb/rf230bb.h"
 #include "net/mac/frame802154.h"
@@ -109,6 +108,8 @@ unsigned char debugflowsize,debugflow[DEBUGFLOWSIZE];
 
 #include "net/rime.h"
 
+#include "params.h"
+
 /* Get periodic prints from idle loop, from clock seconds or rtimer interrupts */
 /* Use of rtimer will conflict with other rtimer interrupts such as contikimac radio cycling */
 /* STAMPS will print ENERGEST outputs if that is enabled. */
@@ -143,8 +144,10 @@ SIGNATURE = {
 };
 #endif
 
+#if !MCU_CONF_LOW_WEAR
 /* JTAG, SPI enabled, Internal RC osc, Boot flash size 4K, 6CK+65msec delay, brownout disabled */
 FUSES ={.low = 0xe2, .high = 0x99, .extended = 0xff,};
+#endif
 
 /* Get a pseudo random number using the ADC */
 uint8_t
@@ -193,6 +196,10 @@ void initialize(void)
   if(MCUSR & (1<<WDRF )) PRINTD("Watchdog reset!\n");
   if(MCUSR & (1<<JTRF )) PRINTD("JTAG reset!\n");
   MCUSR = 0;
+  
+  PRINTD("CLOCK_SECOND %d\n",CLOCK_SECOND);
+  PRINTD("RTIMER_ARCH_SECOND %lu\n",RTIMER_ARCH_SECOND);
+  PRINTD("F_CPU %lu\n",F_CPU);
 
 #if STACKMONITOR
   /* Simple stack pointer highwater monitor. Checks for magic numbers in the main

platform/avr-raven/params.h

@@ -6,7 +6,7 @@
  *   This allows parameter changes using a hardware programmer or custom application code.
  *   Corruption test is based on channel verify so get the channel before anything else!
  * 2 Obtained from eeprom using the general settings manager and read from program flash if not present.
- *   Useful for for testing builds without wearing out flash memory.
+ *   Useful for for testing builds without wearing out eeprom memory.
  * 3 Obtained from eeprom using the settings manager and rewritten from flash if not present.
  *   This ensures all parameters are present in upper eeprom flash.
  *
@@ -21,10 +21,18 @@
 //#define CONTIKI_CONF_RANDOM_MAC 1        //adds 78 bytes
 
 #if CONTIKI_CONF_SETTINGS_MANAGER
+#if MCU_CONF_LOW_WEAR
 #define PARAMETER_STORAGE 2
 #else
+#define PARAMETER_STORAGE 3
+#endif
+#else
+#if MCU_CONF_LOW_WEAR
+#define PARAMETER_STORAGE 0
+#else
 #define PARAMETER_STORAGE 1
 #endif
+#endif
 
 /* Include settings.h, then dummy out the write routines */
 #include "settings.h"