smiw - 8051

    org 0
    mov p3, #00h
reset:
    mov p3, #FEh
start:
    jb p1.0, moveBit
    sjmp start

moveBit:
    jb p1.1, moveRight
    sjmp moveLeft

moveRight:
    mov A, p3
    rr A
    mov p3, A
    sjmp start


moveLeft:
    mov A, p3
    rl A
    mov p3, A
    sjmp start