Logical shift right accumulator

def instruction_LSR_register(self, opcode, register):
        """ Logical shift right accumulator """
        a = register.value
        r = self.LSR(a)
#        log.debug("$%x LSR %s value $%x >> 1 = $%x" % (
#            self.program_counter,
#            register.name, a, r
#        ))
        register.set(r)