AVR Freaks

/*
 *
 * Atmel XMega 128A1 Current measurement Test harness, and PLL setup
 * example.
 *
 * V1.0 Bob Paddock Sep/1/2009
 *
 * Compile with WinAVR-200901313 GCC 4.3.2 or newer.
 *
 * Test configuration is power supply set to 3.7V, in series with
 * current meter on the positive lead, into a three volt regulator,
 * which is powering XMega 128A1.  Only XMega ports PQ0 and PQ1 are
 * connected to 32 kHz watch crystal, all other pins are floating,
 * except PK1->PK6 that have 1k external pull-ups.  Current meter
 * does not read below 1uA.
 *
 * A board with *no* XMega populated takes 5 uA for reset chip,
 * voltage regulator quiescent current, cap leakage etc.
 *
 * Test measurement currents are with Clock Out (PD7) disabled, and not
 * loaded.  Each measurement taken with JTAG unplugged, and power cycled.
 *
 * The set of defines below will allow running the XMega at
 * frequencies of 32 kHz, 2 MHz, 4 MHz, 16 MHz and 32 MHz, with
 * options for auto calibration, and RTC to be enabled.  With no
 * options test runs at default 2 MHz.
 *
 */

#include 
#include  /* _NOP() */

#include "ccpwrite.h"
#include "clksys_driver.h"
#include "rtc_driver.h" /* RTC_BUSY() */

/* Settings as shown run at 2 MHz: */
#define USE_CLOCK_OUT_ON_D7  (0) /* Non-zero for clock out on PD7.  Do not set when measuring current */

#define USE_SLEEP            (0) /* Non-Zero to enter sleep, otherwise use empty NOP loop */
#define USE_RTC              (0) /* Non-zero to enable RTC at 1 kHz */

#define ENABLE_16MHZ_PLL     (0) /* Non-zero to run at 16 MHz */
#define ENABLE_32MHZ_PLL     (0) /* Non-zero to run at 32 MHz */
#define ENABLE_PLL_DIV_4     (0) /* Non-zero to divide PLL by 4.  Will give 4 MHz with 16 MHz PLL, and 8 MHz with 32 MHz PLL */

#define USE_32kHz_CRYSTAL    (0) /* Non-zero to enable external 32.768 kHz Watch Crystal for auto calibration and running at 32 kHz */
#define USE_AUTO_CALIBRATION (0) /* Non-zero to use external crystal as reference for the internal 2 MHz Osc., not used at 32 kHz */
#define RUN_AT_32KHZ         (0)

/* Generate error message(s) if have incompatible options selected: */

#if( (ENABLE_16MHZ_PLL > 0) && (ENABLE_32MHZ_PLL > 0) )
#error Both 16 and 32 MHz settings may not be enabled simultaneously
#endif

#if( (ENABLE_PLL_DIV_4 > 0) && (0 == ENABLE_16MHZ_PLL) && (0 == ENABLE_32MHZ_PLL) )
#error ENABLE_16MHZ_PLL or ENABLE_32MHZ_PLL must be set to use ENABLE_PLL_DIV_4
#endif

#if( (USE_32kHz_CRYSTAL < 1) && (USE_AUTO_CALIBRATION > 0) )
#error USE_32kHz_CRYSTAL must be set to use Auto Calibration.
#endif

#if( RUN_AT_32KHZ > 0 )

#if( 0 == USE_32kHz_CRYSTAL )
#error USE_32kHz_CRYSTAL must be set to run at 32 kHz
#endif

#if( (ENABLE_16MHZ_PLL > 0) || (ENABLE_32MHZ_PLL > 0) )
#error 16 or 32 MHz PLL settings may not be enabled when running at 32 kHz
#endif

#if( ENABLE_PLL_DIV_4 > 0 )
#error ENABLE_PLL_DIV_4 may not be enabled when running at 32 kHz
#endif

#endif /* #if( RUN_AT_32KHZ > 0 ) */

/*
 * 2 MHz Osc. running, 32 kHz Osc. Off, Auto Calibration Off, RTC Off:
 * Empty loop, inputs floating:         Wondering around 3.00 mA
 * Empty loop, inputs pulled-up:        2.31 mA
 *
 * 2 MHz Osc. running, 32 kHz Osc. On, Auto Calibration Off, RTC Off:
 * Empty loop, inputs pulled-up:        2.28 mA [Went down?]
 *
 * 2 MHz Osc. running, 32 kHz Osc. On, Auto Calibration On, RTC Off:
 * Empty loop, inputs pulled-up:        2.29 mA
 *
 * 2 MHz Osc. running, 32 kHz Osc. On, Auto Calibration On, RTC On:
 * Empty loop, inputs pulled-up:        2.31 mA
 *
 * 2 MHz Osc. running, 32 kHz Osc. On, Auto Calibration On, RTC On, 16 MHz PLL:
 * Empty loop, inputs pulled-up:        16.18 mA
 *
 * 2 MHz Osc. running, 32 kHz Osc. On, Auto Calibration On, RTC On, 16 MHz PLL/4 (4 MHz):
 * Empty loop, inputs pulled-up:        4.87 mA
 *
 * 2 MHz Osc. running, 32 kHz Osc. On, Auto Calibration On, RTC On, 32 MHz PLL:
 * Empty loop, inputs pulled-up:        30.49 mA
 *
 * 2 MHz Osc. running, 32 kHz Osc. On, Auto Calibration On, RTC On, 32 MHz PLL/4 (8 MHz):
 * Empty loop, inputs pulled-up:        9.29 mA
 *
 * 2 MHz Osc. stopped, running at 32 kHz, Auto Calibration Off, RTC On:
 * Empty loop, inputs pulled-up:        180 uA
 *
 * At 2 MHz settings and 32 kHz Osc., stopped:
 *      RTC Off:
 *      PDOWN:                          5 uA
 *      PSAVE:                          5 uA
 *
 *      RTC On at 1024 Hz, 32 kHz *Off* (not useful):
 *      PSAVE:                          6 uA
 *
 *      RTC On at 1024 Hz, 32 kHz On:
 *      PSAVE:                          6 uA
 */

int main( void )
{

#if 0 /* Simple Empty loop.  Floating inputs, always bad design practice */
  for(;;)
    {
      _NOP();
    }
#endif

#if 1 /* Pull-ups enabled */
 /*
  * Reset has all port pins as inputs.
  * Set all pins to have internal pull-ups:
  */
  PORTCFG.MPCMASK = (uint8_t) -1; /* MPCMASK register is cleared automatically after the write operation to the pin configuration registers is finished. */
  PORTA.PIN0CTRL = PORT_OPC_PULLUP_gc;

  PORTCFG.MPCMASK = (uint8_t) -1;
  PORTB.PIN0CTRL = PORT_OPC_PULLUP_gc;

  PORTCFG.MPCMASK = (uint8_t) -1;
  PORTC.PIN0CTRL = PORT_OPC_PULLUP_gc;

  PORTCFG.MPCMASK = (uint8_t) -1;
  PORTD.PIN0CTRL = PORT_OPC_PULLUP_gc;

  PORTCFG.MPCMASK = (uint8_t) -1;
  PORTE.PIN0CTRL = PORT_OPC_PULLUP_gc;

  PORTCFG.MPCMASK = (uint8_t) -1;
  PORTF.PIN0CTRL = PORT_OPC_PULLUP_gc;

  PORTCFG.MPCMASK = (uint8_t) -1;
  PORTH.PIN0CTRL = PORT_OPC_PULLUP_gc;

  PORTCFG.MPCMASK = (uint8_t) -1;
  PORTJ.PIN0CTRL = PORT_OPC_PULLUP_gc;

  PORTCFG.MPCMASK = (uint8_t) -1;
  PORTK.PIN0CTRL = PORT_OPC_PULLUP_gc;

  PORTCFG.MPCMASK = (uint8_t) -1;
  PORTQ.PIN0CTRL = PORT_OPC_PULLUP_gc; /* PQ0 and PQ1 have 32.768 kHz Watch Crystal connected */

  PORTCFG.MPCMASK = (uint8_t) -1;
  PORTR.PIN0CTRL = PORT_OPC_PULLUP_gc;

#if( USE_CLOCK_OUT_ON_D7 > 0 )
  PORTD.DIRSET =  _BV(7);                   /* To output clock, port must be set as output */
  PORTCFG.CLKEVOUT = PORTCFG_CLKOUT_PD7_gc; /* Output the clock frequency on PD7 to measure on Counter/Scope */
#endif

#if( USE_32kHz_CRYSTAL > 0 )
  CLKSYS_XOSC_Config( 0, false, OSC_XOSCSEL_32KHz_gc );
  CLKSYS_Enable( (OSC_RC2MEN_bm|OSC_XOSCEN_bm) );        /* Does an OR with current Osc bits */
  do {} while ( CLKSYS_IsReady( OSC_XOSCRDY_bm ) == 0 ); /* 32 kHz Does AND of the bits */
#else
  CLKSYS_Enable( (OSC_RC2MEN_bm) );   /* Does an OR with current Osc bits */
#endif

  do {} while ( CLKSYS_IsReady( OSC_RC2MRDY_bm ) == 0 ); /* Wait for 2 MHz Osc. to stabilize */
  /* At Reset, the main clock source will already be the 2 MHz Osc. */

#if( (USE_32kHz_CRYSTAL > 0) && (USE_AUTO_CALIBRATION > 0) )
  CLKSYS_AutoCalibration_Enable( OSC_RC2MCREF_bm, true ); /* 2MHz Osc. True= external crystal used as reference */
#endif

#if( USE_RTC > 0 )
  CLKSYS_RTC_ClockSource_Enable( CLK_RTCSRC_TOSC_gc ); /* RTC source is 1024 Hz from 32kHz crystal oscillator on TOSC */
  while( RTC_Busy() )
    ;
  RTC.PER  = 2000;
  RTC.COMP = 1000;
  RTC.CNT  = 0;
  //  RTC.CTRL = RTC_PRESCALER_DIV1024_gc; /* Rollover in 18 hours and 12 minutes */
  RTC.CTRL = RTC_PRESCALER_DIV1_gc; /* Rollover at 64 seconds */
#endif

#if( ENABLE_16MHZ_PLL > 0 )
  CLKSYS_PLL_Config( OSC_PLLSRC_RC2M_gc, 8 );             /* 2MHz * 8 = 16 MHz.  PLL Min is 10 MHz */
#endif

#if( ENABLE_32MHZ_PLL > 0 )
  CLKSYS_PLL_Config( OSC_PLLSRC_RC2M_gc, 16 );            /* 2MHz * 16 = 32 MHz.  PLL Min is 10 MHz */
#endif

#if( ENABLE_PLL_DIV_4 > 0 )
  CLKSYS_Prescalers_Config( CLK_PSADIV_4_gc, CLK_PSBCDIV_1_1_gc ); /* CLKper = CLKcpu = PLL MHz/4.  PrescalerC drives CLKcpu */
#endif

#if( (ENABLE_16MHZ_PLL > 0) || (ENABLE_32MHZ_PLL > 0) )
  CLKSYS_Enable( OSC_PLLEN_bm );
  do {} while ( CLKSYS_IsReady( OSC_PLLRDY_bm ) == 0 );

  CLKSYS_Main_ClockSource_Select( CLK_SCLKSEL_PLL_gc );   /* Switch main clock PLL */
#endif

#if( RUN_AT_32KHZ > 0 )

#if( USE_AUTO_CALIBRATION > 0 )
  CLKSYS_AutoCalibration_Disable( DFLLRC2M ); /* Turn off the 2MHz Auto Calibration so we can switch Osc. to 32 kHz */
#endif

  CLKSYS_Main_ClockSource_Select( CLK_SCLKSEL_XOSC_gc );  /* Switch external 32 kHz watch crystal */

  (void) CLKSYS_Disable( OSC_RC2MEN_bm );/* Disable the 2 MHz osc now that we are not using it */
#endif

#if( USE_SLEEP > 0 )
  CCPWrite(&MCU.MCUCR, MCU_JTAGD_bm);    /* Disables JTAG during sleep */

  SLEEP.CTRL  = (SLEEP_SMODE_PSAVE_gc|SLEEP_SEN_bm);    /* Set sleep mode to Power Save, asynchronous I/O wakeup, RTC runs if enabled, enable Sleep instruction */
#endif

  for(;;)
    {
#if( USE_SLEEP > 0 )
      sleep_cpu();                           /* AVR Sleep instruction */
#else
      _NOP();
#endif
    }


#endif /* Pull-ups enabled */

}/* main() */