tinygo/src/runtime/runtime_attiny.go

// +build avr,attiny

package runtime

import (
	"device/avr"
)

func sleepWDT(period uint8) {
	// TODO: use the watchdog timer instead of a busy loop.
	for i := 0x45; i != 0; i-- {
		for i := 0xff; i != 0; i-- {
			avr.Asm("nop")
		}
	}
}