ATTiny 85 random blink

random-led

void setup() {
asm volatile(R"(
  ldi r16, 0b00001000
  out 0x17, r16
  ldi r19, 1
  ldi r20, 1
task1:  
  ldi r16, 0b00001000 
  out 0x18, r16 
  rcall delay0  
  ldi r16, 0b00000000 
  out 0x18, r16 
  rcall delay0  
  rjmp task1  

delay0: 
  rcall rand0
  mov r17, r20
delay1: 
  ldi r18, 0  
delay2: 
  dec r18 
  brne delay2 
  dec r17 
  brne delay1 
  ret

rand0:
  mov r21, r19
  add r19, r20
  mov r20, r21
  ret
)");
}

void loop() {
}