Semiconductor integrated circuit and circuit operation method
The power consumption of a data sampling unit that selects a phase of a clock signal appropriate for sampling payload data is reduced at an input interface. A semiconductor integrated circuit includes an input interface and internal core circuits. The input interface includes a hysteresis circuit and a data sampling unit. The hysteresis circuit detects an input signal between first and second input thresholds as a sleep command. The data sampling unit selects an appropriate phase of a sampling clock signal in accordance with a synchronizing signal and samples payload data. When a sleep command is detected, a sleep signal is also supplied to the internal core circuits and the data sampling unit and they are controlled into a low-power consumption state.
1. A semiconductor integrated circuit comprising:
an input interface externally supplied with an input signal; and
an internal core circuit supplied with signal data generated at the input interface as the result of reception of the input signal by the input interface,
wherein the input interface comprises a hysteresis circuit and a data sampling unit,
wherein the hysteresis circuit of the input interface has a first input threshold and a second input threshold and thus the hysteresis circuit detects as a sleep command the input signal having a predetermined voltage range between the first input threshold and the second input threshold,
wherein the data sampling unit of the input interface selects a phase of a sampling clock signal appropriate to sample data according to the data pattern of a synchronizing signal supplied as the input signal and the data sampling unit uses a sampling clock signal having the selected phase to sample payload data contained in the input signal,
wherein when the hysteresis circuit of the input interface detects the sleep command, a sleep signal generated at the hysteresis circuit is supplied to the internal core circuit and the internal core circuit is controlled into sleep mode in response to the sleep signal,
wherein the sleep signal generated at the hysteresis circuit is also supplied to the data sampling unit of the input interface and as a result the data sampling unit is controlled into sleep mode in response to the sleep signal,
wherein the data sampling unit comprises a plurality of data sampling circuits and a clock selection data determination circuit,
wherein the data sampling circuits sample the data pattern of the synchronizing signal in parallel by a plurality of clock signals different in phase from one another,
wherein the clock selection data determination circuit generates a plurality of clock signal selection signals in response to a plurality of output signals outputted from the data sampling circuits and thereby selects one clock signal as reference clock signal from among the clock signals to generate the sampling clock signal used for sampling the payload data,
wherein after selection of the reference clock signal, one data sampling circuit for generating the selected one clock signal is activated among the data sampling circuits and the other data sampling circuits for generating other unselected clock signals are deactivated,
wherein the data sampling unit stores into a memory the payload data sampled by the sampling clock,
wherein the data sampling unit generates a data end signal in response to the completion of storage of the payload data into the memory,
wherein the input interface further comprises a sleep determination circuit that is supplied with the sleep signal generated at the hysteresis circuit and the data end signal generated at the data sampling unit and thereby generates a sleep transition signal,
wherein the sleep determination circuit asserts the sleep transition signal in response to both the sleep signal and the data end signal being asserted,
wherein the internal core circuit and the data sampling unit are controlled into the sleep mode in response to the sleep transition signal asserted by the sleep determination circuit, and
wherein the input interface is configured as a differential signal interface supplied with a differential input signal as the input signal.
2. The semiconductor integrated circuit according to claim 1 ,
wherein the data sampling unit generates the data end signal based on the data size information of a header contained in the input signal.
3. The semiconductor integrated circuit according to claim 1 ,
wherein the hysteresis circuit of the input interface is coupled with a sleep transition bit determination circuit, and
wherein the sleep transition bit determination circuit determines the level of a sleep transition bit during a bit period immediately after the last bit of the payload data.
4. The semiconductor integrated circuit according to claim 1 ,
wherein the hysteresis circuit of the input interface comprises a plurality of differential amplifiers responding to the differential input signal as the input signal and a sleep detection circuit responding to a differential output signal of at least one differential amplifier of the differential amplifiers, and
wherein the hysteresis circuit of the input interface thereby operates as a window comparator that detects as the sleep command the input signal having the predetermined voltage range between the first input threshold and the second input threshold.
5. The semiconductor integrated circuit according to claim 1 ,
wherein the input interface configured as the differential signal interface is a digital interface and the digital interface is supplied with a differential digital baseband signal,
wherein the differential digital baseband signal is converted into a large-amplitude digital baseband signal having an amplitude signal larger than the differential amplitude of the differential digital baseband signal by the hysteresis circuit and the data sampling unit of the input interface,
wherein the internal core circuit comprises a D-A converter for transmission and an up conversion transmission circuit,
wherein the large-amplitude digital baseband signal from the input interface can be converted into an analog transmit baseband signal by the D-A converter for transmission, and
wherein the analog transmit baseband signal from the D-A converter for transmission can be converted into an RF transmission signal by the up conversion transmission circuit.
6. The semiconductor integrated circuit according to claim 5 ,
wherein the data sampling unit uses the sampling clock signal to carry out serial-parallel conversion of the input signal.
7. An operation method for a semiconductor integrated circuit comprising:
receiving an externally supplied input signal via an input interface; and
supplying an internal core circuit with signal data generated at the input interface as a result of reception of the input signal by the input interface,
wherein the input interface comprises a hysteresis circuit and a data sampling unit,
wherein the hysteresis circuit of the input interface has a first input threshold and a second input threshold and thus the hysteresis circuit detects as a sleep command the input signal having a predetermined voltage range between the first input threshold and the second input threshold,
wherein the data sampling unit of the input interface selects a phase of a sampling clock signal appropriate to sample data according to the data pattern of a synchronizing signal supplied as the input signal and the data sampling unit uses a sampling clock signal having the selected phase to sample payload data contained in the input signal,
wherein when the hysteresis circuit of the input interface detects the sleep command, a sleep signal generated at the hysteresis circuit is supplied to the internal core circuit and the internal core circuit is controlled into sleep mode in response to the sleep signal,
wherein the sleep signal generated at the hysteresis circuit is also supplied to the data sampling unit of the input interface and as a result the data sampling unit is controlled into sleep mode in response to the sleep signal,
wherein the data sampling unit comprises a plurality of data sampling circuits and a clock selection data determination circuit,
wherein the data sampling circuits sample the data pattern of the synchronizing signal in parallel by a plurality of clock signals different in phase from one another,
wherein the clock selection data determination circuit generates a plurality of clock signal selection signals in response to a plurality of output signals outputted from the data sampling circuits and thereby selects one clock signal as reference clock signal from among the clock signals to generate the sampling clock signal used for sampling the payload data,
wherein after selection of the reference clock signal, one data sampling circuit for generating the selected one clock signal is activated among the data sampling circuits and the other data sampling circuits for generating other unselected clock signals are deactivated,
wherein the data sampling unit stores into a memory the payload data sampled by the sampling clock,
wherein the data sampling unit generates a data end signal in response to the completion of storage of the payload data into the memory,
wherein the input interface further comprises a sleep determination circuit that is supplied with the sleep signal generated at the hysteresis circuit and the data end signal generated at the data sampling unit and thereby generates a sleep transition signal,
wherein the sleep determination circuit asserts the sleep transition signal in response to both the sleep signal and the data end signal being asserted,
wherein the internal core circuit and the data sampling unit are controlled into the sleep mode in response to the sleep transition signal asserted by the sleep determination circuit, and
wherein the input interface is configured as a differential signal interface supplied with a differential input signal as the input signal.
8. The operation method for the semiconductor integrated circuit according to claim 7 ,
wherein the data sampling unit generates the data end signal based on the data size information of a header contained in the input signal.
9. The operation method for the semiconductor integrated circuit according to claim 7 ,
wherein the hysteresis circuit of the input interface is coupled with a sleep transition bit determination circuit, and
wherein the sleep transition bit determination circuit determines the level of a sleep transition bit during a bit period immediately after the last bit of the payload data.
10. The operation method for the semiconductor integrated circuit according to claim 7 ,
wherein the hysteresis circuit of the input interface comprises a plurality of differential amplifiers responding to the differential input signal as the input signal and a sleep detection circuit responding to a differential output signal of at least one differential amplifier of the differential amplifiers, and
wherein the hysteresis circuit of the input interface operates as a window comparator that detects as the sleep command the input signal having the predetermined voltage range between the first input threshold and the second input threshold.
11. The operation method for the semiconductor integrated circuit according to claim 7 ,
wherein the input interface configured as the differential signal interface is a digital interface and the digital interface is supplied with a differential digital baseband signal,
wherein the differential digital baseband signal is converted into a large-amplitude digital baseband signal having an amplitude signal larger than the differential amplitude of the differential digital baseband signal by the hysteresis circuit and the data sampling unit of the input interface,
wherein the internal core circuit comprises a D-A converter for transmission and an up conversion transmission circuit,
wherein the large-amplitude digital baseband signal from the input interface can be converted into an analog transmit baseband signal by the D-A converter for transmission, and
wherein the analog transmit baseband signal from the D-A converter for transmission can be converted into an RF transmission signal by the up conversion transmission circuit.
12. The operation method for the semiconductor integrated circuit according to claim 11 ,
wherein the data sampling unit uses the sampling clock signal to carry out serial-parallel conversion of the input signal.