+ /* Configure OCR1A as an output for the specified AVR model */
+ #if defined(USB_SERIES_2_AVR)
+ DDRC |= (1 << 6);
+ #else
+ DDRB |= (1 << 5);
+ #endif
+
+ /* Start Timer 1 to generate a 4MHz clock on the OCR1A pin */
+ TIMSK1 = 0;
+ TCNT1 = 0;
+ OCR1A = ((F_CPU / 2 / ISP_RESCUE_CLOCK_SPEED) - 1);
+ TCCR1A = (1 << COM1A0);
+ TCCR1B = ((1 << WGM12) | (1 << CS10));