def instruction_ST16(self, opcode, ea, register):
        """
        Writes the contents of a 16-bit register into two consecutive memory
        locations.

        source code forms: STD P; STX P; STY P; STS P; STU P

        CC bits "HNZVC": -aa0-
        """
        value = register.value
#        log.debug("$%x ST16 store value $%x from %s at $%x \t| %s" % (
#             self.program_counter,
#             value, register.name, ea,
#             self.cfg.mem_info.get_shortest(ea)
#         ))
        self.clear_NZV()
        self.update_NZ_16(value)
        return ea, value