jump_bootloader.c

   1 // this code from:
   2 // http://www.pjrc.com/teensy/jump_to_bootloader.html
   3 #include <avr/io.h>
   4 #include <avr/interrupt.h>
   5 #include <util/delay.h>
   6
   7 void jump_bootloader(void) {
   8     cli();
   9     // disable watchdog, if enabled
  10     // disable all peripherals
  11     UDCON = 1;
  12     USBCON = (1<<FRZCLK);  // disable USB
  13     UCSR1B = 0;
  14     _delay_ms(5);
  15 #if defined(__AVR_AT90USB162__)                // Teensy 1.0
  16     EIMSK = 0; PCICR = 0; SPCR = 0; ACSR = 0; EECR = 0;
  17     TIMSK0 = 0; TIMSK1 = 0; UCSR1B = 0;
  18     DDRB = 0; DDRC = 0; DDRD = 0;
  19     PORTB = 0; PORTC = 0; PORTD = 0;
  20     asm volatile("jmp 0x3E00");
  21 #elif defined(__AVR_ATmega32U4__)              // Teensy 2.0
  22     EIMSK = 0; PCICR = 0; SPCR = 0; ACSR = 0; EECR = 0; ADCSRA = 0;
  23     TIMSK0 = 0; TIMSK1 = 0; TIMSK3 = 0; TIMSK4 = 0; UCSR1B = 0; TWCR = 0;
  24     DDRB = 0; DDRC = 0; DDRD = 0; DDRE = 0; DDRF = 0; TWCR = 0;
  25     PORTB = 0; PORTC = 0; PORTD = 0; PORTE = 0; PORTF = 0;
  26     asm volatile("jmp 0x7E00");
  27 #elif defined(__AVR_AT90USB646__)              // Teensy++ 1.0
  28     EIMSK = 0; PCICR = 0; SPCR = 0; ACSR = 0; EECR = 0; ADCSRA = 0;
  29     TIMSK0 = 0; TIMSK1 = 0; TIMSK2 = 0; TIMSK3 = 0; UCSR1B = 0; TWCR = 0;
  30     DDRA = 0; DDRB = 0; DDRC = 0; DDRD = 0; DDRE = 0; DDRF = 0;
  31     PORTA = 0; PORTB = 0; PORTC = 0; PORTD = 0; PORTE = 0; PORTF = 0;
  32     asm volatile("jmp 0xFC00");
  33 #elif defined(__AVR_AT90USB1286__)             // Teensy++ 2.0
  34     EIMSK = 0; PCICR = 0; SPCR = 0; ACSR = 0; EECR = 0; ADCSRA = 0;
  35     TIMSK0 = 0; TIMSK1 = 0; TIMSK2 = 0; TIMSK3 = 0; UCSR1B = 0; TWCR = 0;
  36     DDRA = 0; DDRB = 0; DDRC = 0; DDRD = 0; DDRE = 0; DDRF = 0;
  37     PORTA = 0; PORTB = 0; PORTC = 0; PORTD = 0; PORTE = 0; PORTF = 0;
  38     asm volatile("jmp 0x1FC00");
  39 #endif
  40 }