• _handler_table_initialized : sercom_interrupt.c
• _sercom_instances : sercom_interrupt.c , sercom_interrupt.h
• _sercom_interrupt_handlers : sercom_interrupt.c
• _system_clock_inst : clock.c
• cpu_irq_critical_section_counter : interrupt_sam_nvic.h
• cpu_irq_prev_interrupt_state : interrupt_sam_nvic.h
• cycles_per_ms : systick_counter.c
• cycles_per_us : systick_counter.c
• dummy_write : spi_interrupt.c
• ssd1306_master : ssd1306.c , ssd1306.h
• ssd1306_slave : ssd1306.c , ssd1306.h