Integrated circuit
An integrated circuit multiplexes transmission data faster than by a system clock, and transfers a timing pulse Txclk for that multiplexing and a multiplexed signal Txdata from a transmitter chip 100 to a receiver chip 150 through communications by inductive coupling, respectively. Because of a transfer by inductive coupling being broadband, close-proximity wireless communications, the receiver chip 150 can faithfully obtain timing information on the timing pulse Txclk including jitter generated by a simple oscillator, and can thus accurately restore original data even by a high-speed transmission. This allows, in an integrated circuit that carries out communications by inductive coupling between chips to be stacked and mounted, carrying out communications between semiconductor chips with a small required area and faster than by a system clock.
1. An integrated circuit comprising:
a transmitter chip including:
a pulse generator for generating i (i is an integer i≧2) timing pulses for transmitting data from a system clock;
a multiplexer for multiplexing transmission data to j:1 (j is an integer 2≦j≦2i) by said timing pulse;
a first transmitter for transmitting by inductive coupling a multiplexed signal multiplexed by said multiplexer;
a second transmitter for transmitting said timing pulse by inductive coupling; and
a receiver chip being stacked and mounted on said transmitter chip including:
a first receiver for receiving said multiplexed signal by inductive coupling;
a second receiver for receiving said timing pulse by inductive coupling; and
a demultiplexer for demultiplexing said multiplexed signal to 1:j by said timing pulse.
2. The integrated circuit according to claim 1 , further comprising a phase interpolator for generating an interpolation timing pulse of a 90 degrees phase to said timing pulse from said timing pulse,
wherein said demultiplexer demultiplexes said multiplexed signal by said interpolation timing pulse.
3. The integrated circuit according to claim 1 , wherein said first transmitter comprises a transmitter coil for transmitting said multiplexed signal by inductive coupling, and enters a signal resulting from said multiplexed signal to one end of said transmitter coil and enters a signal resulting from a reverse polarity signal of said multiplexed signal to an other end of said transmitter coil to enter a waveform equivalent to a waveform of said multiplexed signal to said transmitter coil.
4. The integrated circuit according to claim 3 , wherein said first receiver comprises a receiver coil for receiving said multiplexed signal by inductive coupling, and forms a hysteresis circuit that repeats, first, inverting output when a voltage induced in said receiver coil exceeds a first threshold value, secondly, inverting output when a voltage induced in said receiver coil falls under a second threshold value smaller than said first threshold value, thirdly, inverting output when a voltage induced in said receiver coil exceeds said first threshold value, and so on.
5. The integrated circuit according to claim 1 , wherein said first receiver comprises a receiver coil for receiving said multiplexed signal by inductive coupling, and biases a center of said receiver coil toward a predetermined potential, and a circuit for generating a bias voltage is a circuit, having a same configuration as that of said first receiver, whose input and output are short-circuited or short-circuited through resistance.