/*
     IAR startup file for AT91SAM7S microcontrollers.
*/

        MODULE  ?cstartup

       ;; Forward declaration of sections.
        SECTION IRQ_STACK:DATA:NOROOT(2)
        SECTION CSTACK:DATA:NOROOT(3)

//------------------------------------------------------------------------------
//         Headers
//------------------------------------------------------------------------------

#define __ASSEMBLY__
#include "at91sam7s256/AT91SAM7S256.h"

//------------------------------------------------------------------------------
//         Definitions
//------------------------------------------------------------------------------

#define ARM_MODE_ABT     0x17
#define ARM_MODE_FIQ     0x11
#define ARM_MODE_IRQ     0x12
#define ARM_MODE_SVC     0x13
#define ARM_MODE_SYS     0x1F

#define I_BIT            0x80
#define F_BIT            0x40

//------------------------------------------------------------------------------
//         Startup routine
//------------------------------------------------------------------------------

/*
   Exception vectors
*/
        SECTION .vectors:CODE:NOROOT(2)

        PUBLIC  resetVector
        PUBLIC  irqHandler

        EXTERN  Undefined_Handler
        EXTERN  SWI_Handler
        EXTERN  Prefetch_Handler
        EXTERN  Abort_Handler
        EXTERN  FIQ_Handler

        ARM

__iar_init$$done:              ; The interrupt vector is not needed
                               ; until after copy initialization is done

resetVector:
       ; All default exception handlers (except reset) are
       ; defined as weak symbol definitions.
       ; If a handler is defined by the application it will take precedence.
        LDR     pc, =resetHandler       ; Reset
        LDR     pc, Undefined_Addr      ; Undefined instructions
        LDR     pc, SWI_Addr            ; Software interrupt (SWI/SYS)
        LDR     pc, Prefetch_Addr       ; Prefetch abort
        LDR     pc, Abort_Addr          ; Data abort
        B       .                       ; RESERVED
        LDR     pc, =irqHandler         ; IRQ
        LDR     pc, FIQ_Addr            ; FIQ

Undefined_Addr: DCD   Undefined_Handler
SWI_Addr:       DCD   SWI_Handler
Prefetch_Addr:  DCD   Prefetch_Handler
Abort_Addr:     DCD   Abort_Handler
FIQ_Addr:       DCD   FIQ_Handler
    
/*
   Handles incoming interrupt requests by branching to the corresponding
   handler, as defined in the AIC. Supports interrupt nesting.
*/
irqHandler:
        /* Save interrupt context on the stack to allow nesting */
        SUB     lr, lr, #4
        STMFD   sp!, {lr}
        MRS     lr, SPSR
        STMFD   sp!, {r0, lr}

        /* Write in the IVR to support Protect Mode */
        LDR     lr, =AT91C_BASE_AIC
        LDR     r0, [r14, #AIC_IVR]
        STR     lr, [r14, #AIC_IVR]

        /* Branch to interrupt handler in Supervisor mode */
        MSR     CPSR_c, #ARM_MODE_SYS
        STMFD   sp!, {r1-r3, r4, r12, lr}
        MOV     lr, pc
        BX      r0
        LDMIA   sp!, {r1-r3, r4, r12, lr}
        MSR     CPSR_c, #ARM_MODE_IRQ | I_BIT

        /* Acknowledge interrupt */
        LDR     lr, =AT91C_BASE_AIC
        STR     lr, [r14, #AIC_EOICR]

        /* Restore interrupt context and branch back to calling code */
        LDMIA   sp!, {r0, lr}
        MSR     SPSR_cxsf, lr
        LDMIA   sp!, {pc}^


/*
   After a reset, execution starts here, the mode is ARM, supervisor
   with interrupts disabled.
   Initializes the chip and branches to the main() function.
*/
        SECTION .cstartup:CODE:NOROOT(2)

        PUBLIC  resetHandler
        EXTERN  LowLevelInit
        EXTERN  ?main
        REQUIRE resetVector
        ARM

resetHandler:

        /* Set pc to actual code location (i.e. not in remap zone) */
        LDR     pc, =label

        /* Perform low-level initialization of the chip using LowLevelInit() */
label:
        LDR     r0, =LowLevelInit
        LDR     r4, =SFE(CSTACK)
        MOV     sp, r4
        MOV     lr, pc
        BX      r0

        /* Set up the interrupt stack pointer. */
        MSR     cpsr_c, #ARM_MODE_IRQ | I_BIT | F_BIT     ; Change the mode
        LDR     sp, =SFE(IRQ_STACK)

        /* Set up the SYS stack pointer. */
        MSR     cpsr_c, #ARM_MODE_SYS | F_BIT             ; Change the mode
        LDR     sp, =SFE(CSTACK)

        /* Branch to main() */
        LDR     r0, =?main
        MOV     lr, pc
        BX      r0

        /* Loop indefinitely when program is finished */
loop4:
        B       loop4

        END

//------------------------------------------------------------------------------
/// Interrupt handler for the PWM controller. Counts the number of periods and
/// updates the duty cycle after a given number.
//------------------------------------------------------------------------------
void ISR_Pwmc(void)
{
    static unsigned int count = 0;
    static unsigned int duty = MIN_DUTY_CYCLE;
    static unsigned char fade = 1;
    
    m_pPio->PIO_CODR = BIT18;  //для проверки входа в прерывание зажигаем светодиод
    

    // Interrupt on channel #0
    if ((AT91C_BASE_PWMC->PWMC_ISR & AT91C_PWMC_CHID0) == AT91C_PWMC_CHID0)
      {
      
        count++;
        if (count == 5000) //раз в полсекунды меняем длительность импульса
         {
          printf("new duty=%u", duty);
          count = 0;
          duty = fade ? duty+1 : duty-1;
          PWMC_SetDutyCycle(CHANNEL_PWM0, duty);
          //PWMC_SetDutyCycle(CHANNEL_PWM1, duty);
          //PWMC_SetDutyCycle(CHANNEL_PWM2, duty);
          //PWMC_SetDutyCycle(CHANNEL_PWM3, duty);
          if (duty == MAX_DUTY_CYCLE || duty == MIN_DUTY_CYCLE)
           {
             fade ^= 1;
           }
         }
       }
  

}

int main(void)
{
    
     //__disable_interrupt(); //пробовал, непомогло
  
    // DBGU output configuration
    TRACE_CONFIGURE(DBGU_STANDARD, 9600, BOARD_MCK);
    printf("-- Getting Started Project %s --\n\r", SOFTPACK_VERSION);
    printf("-- %s\n\r", BOARD_NAME);
    printf("-- Compiled: %s %s --\n\r", __DATE__, __TIME__);
    printf("Sasha's compilation\n\r");
    
  // Configure led
  m_pPio->PIO_SODR  = BIT18;   // Set PA18 to HIGH -> led off
  m_pPio->PIO_OER   = BIT18;   // Configure PA8 as output
  

   //Configure PIO
    PIO_Configure(pins, PIO_LISTSIZE(pins));
    AT91C_BASE_PMC->PMC_PCER = 1 << AT91C_ID_PWMC;
  
  printf("1\n\r");

  // Settings:
  // - 100kHz PWM period (PWM_FREQUENCY)
  // - 1s rise/fall time for the LED intensity

   PWMC_ConfigureClocks(PWM_FREQUENCY * MAX_DUTY_CYCLE, 0, BOARD_MCK);
  
  
  printf("2\n\r");

  // Configure PWMC channel 0 (left-aligned)
  PWMC_ConfigureChannel(CHANNEL_PWM0, AT91C_PWMC_CPRE_MCKA, 0, 0);
  PWMC_SetPeriod(CHANNEL_PWM0, MAX_DUTY_CYCLE);
  PWMC_SetDutyCycle(CHANNEL_PWM0, 3);
    

  //моргаем светодиодом для проверки работоспособности
    unsigned long i;
  for(i = 0; i < 25; i++)
  {
    m_pPio->PIO_CODR = BIT18;    
    Delay(1000000);
    m_pPio->PIO_SODR = BIT18;  
    Delay(1000000);
  }
  

  
   // Configure interrupt on PWM channels #0
  IRQ_ConfigureIT(AT91C_ID_PWMC, 0, ISR_Pwmc);
  
  IRQ_EnableIT(AT91C_ID_PWMC);

  PWMC_EnableChannelIt(CHANNEL_PWM0);

  PWMC_EnableChannel(CHANNEL_PWM0);

//__enable_interrupt(); //пробовал, непомогло


  
  printf("9\n\r");
      
    // Main loop
    while (1)
      {

                      
      }
}