import array

screen=array.array('B',(0b1010_1111,0b0000_1100,0,0))
chunk=array.array('H',range(20))
@micropython.asm_thumb
def test(r0,r1,r2,r3): # from, to, #bytes, color
  label(LOOP)
  ldrb(r4,[r0,0])
  mov(r6,8)
  label(BYTE)
  asr(r4,r4,1)
  bcs(ONE)
  mov(r5,0)
  b(NEXT)
  label(ONE)
  mov(r5,r3)
  label(NEXT)
  strh(r5,[r1,0])
  add(r1,r1,2)
  sub(r6,r6,1)
  bne(BYTE)
  add(r0,r0,1)
  sub(r2,r2,1)
  bne(LOOP)
  label(EXIT)



print(test(screen,chunk,2,0xffff))
print(screen)
print(chunk)