Method for transferring data between devices by generating a strobe pulse and clamping a clock line

摘要

A first and second electronic devices are connected by two data lines arranged in a wired-AND configuration so that each device can signal the other device by forcing one of the two-wires into a "low" condition. An inventive method uses serial transfer of a predetermined numbers of bits in a digital word delimited by start and stop bits which are, in turn, defined by their relation to a clock signal on one of the data lines. The start and stop bits are chosen to be in a particular state during the "active" portion of the clock signal. Thus, the need for clocked gates or multivibrators is eliminated. In the preferred embodiment, the method and apparatus are used in a digital multimeter to intercouple a microprocessor and an electronic measuring circuit so that the microprocessor can control the measuring circuit and receive measured values from the circuit.