摘要:
An offsetting comparator device includes master and slave comparator circuits and a reference differential voltage generator. The master comparator circuit supplies a sensed current corresponding to a potential difference represented by a differential signal on a transmission line. The reference differential voltage generator generates a reference differential voltage based on an intermediate potential of the differential signal. And the slave comparator circuit supplies a current corresponding to the potential difference as offset current. The offsetting comparator device outputs a differential current between the sensed and offset currents and therefore shows an offset in its input/output characteristics. The master and slave comparator circuits have the same circuit configuration. Thus, if the characteristic of the sensed current output from the master comparator circuit has changed due to a potential level variation of the differential signal, then the characteristic of the offset current also changes similarly. Thus, the offsetting comparator device can obtain a constant offset voltage even if the potential level of the differential signal has changed.
摘要:
A data line pair and a strobe line pair are provided between first and second chips to exchange data therebetween. The first chip includes an output circuit and a controller for controlling the output circuit. The second chip includes an input circuit. For example, the output circuit supplies a direct current from a power supply to one of the data lines. Then, the input circuit feeds back the received current to the output circuit through a pair of terminal resistors and the other data line. Subsequently, the output circuit supplies the fed back direct current to one of the strobe lines. In response, the input circuit feeds back the received current again to the output circuit through another pair of terminal resistors and the other strobe line. And then the fed back current is drained to the ground. Thus, compared to driving the data and strobe line pairs separately with the same amount of current supplied, the current dissipation can be halved. In this manner, the present invention is applicable to reduction of current dissipation when data should be transmitted at high speeds through multiple data bus pairs that are driven with a current supplied.
摘要:
In the early half of one period of a main clock, one multiplexer selects a signal Ain, while the other multiplexer selects an inverted signal /Ain. Consequently, the signal Ain is transmitted to a signal line assigned to the signal line Ain, while the signal /Ain is transmitted to a signal line assigned to a signal Bin, thereby accomplishing differential transmission of the signal Ain. In the late half of one period of the main clock, the above one multiplexer selects an inverted signal /Bin, while the above other multiplexer selects the signal Bin. Consequently, the inverted signal /Bin is transmitted to the signal line assigned to the signal Ain, while the signal Bin is transmitted to the signal line assigned to the signal Bin, thereby accomplishing differential transmission of the signal Bin. Since differential transmission is thus accomplished with no increase in the number of wires, power saving can be achieved by data transfer with a small amplitude.
摘要:
In transmitting a first pair of differential clock signals UCLK, UXCLK having an extremely small amplitude voltage based on a power-source potential and a second pair of differential clock signals LCLK, LXCLK having an extremely small amplitude voltage based on the power-source potential, an inverting circuit as a signal receiving circuit is composed of a CMOS inverting circuit. A PMOS transistor composing the CMOS inverting circuit has a gate electrode and a source electrode receiving the first pair of differential clock signals. An NMOS transistor composing the CMOS inverting circuit has a gate electrode and a source electrode receiving the second pair of differential clock signals. When the potentials of the differential clock signals change, potentials at the respective gate and source electrodes of the two transistors shift in opposite directions, which surely cuts off the transistors. Accordingly, the signal receiving circuit composed of the inverting circuit operates statically in response to the first and second pairs of differential signals.
摘要:
In transmitting a first pair of differential clock signals UCLK, UXCLK having an extremely small amplitude voltage based on a power-source potential and a second pair of differential clock signals LCLK, LXCLK having an extremely small amplitude voltage based on the power-source potential, an inverting circuit as a signal receiving circuit is composed of a CMOS inverting circuit. A PMOS transistor composing the CMOS inverting circuit has a gate electrode and a source electrode receiving the first pair of differential clock signals. An NMOS transistor composing the CMOS inverting circuit has a gate electrode and a source electrode receiving the second pair of differential clock signals. When the potentials of the differential clock signals change, potentials at the respective gate and source electrodes of the two transistors shift in opposite directions, which surely cuts off the transistors. Accordingly, the signal receiving circuit composed of the inverting circuit operates statically in response to the first and second pairs of differential signals.
摘要:
Two multiplexors select a first signal Ain and its inverted signal /Ain in the first half of a single cycle of a clock signal and Ain and /Ain, i.e., a differential signal pair, are differential-transmitted to two signal lines. On the other hand, the two multiplexors select a second signal Bin and its inverted signal /Bin in the second half and Bin and /Bin, i.e., a differential signal pair, are differential-transmitted to the two signal lines. Based on the transition probability of Ain and Bin or based on the mode information of a system, either Ain or Bin is selected and is differential-transmitted. As a result of such arrangement, when the transmission of one of Ain and Bin is not required, the other signal can continuously be differential-transmitted using an unoccupied signal line, which makes it possible to increase the rate of signal transmission without having to increase the number of signal lines.
摘要:
An exclusive OR circuit is provided which detects whether or not a preceding-stage logical output value and a subsequent-stage logical output value agree. When these logical output values are found to agree, a NAND circuit functions to cut off the supply of a clock signal to a first and second switch circuits and to a latch circuit. Accordingly, when there occur no data changes between clock signal cycles, in a switch circuit and a latch circuit both arranged between each stage of a pipeline, the charge/discharge of the capacitance of gate electrodes of transistors forming these circuits is prevented, thereby reducing power consumption.
摘要:
A phase adjusting circuit includes a circuit for providing an internal clock signal in synchronization with a reference clock signal, a delay circuit for delaying the internal clock signal for a predetermined delay time and an adjusting section for adjusting a phase difference between a phase of the reference clock signal and a phase of the internal clock signal delayed for the predetermined delay time.
摘要:
An image data memory with a 2-bank (bank A and bank B) structure is disclosed. The bank A stores only even field data, whereas the bank B stores only odd field data, and a peripheral circuit composed of elements such as row decoders and column decoders is provided in such a manner that each bank can be accessed independently of the other. One of the banks A and B is precharged while the other bank is accessed in order that the banks A and B are alternately accessed. Fast frame access is accomplished.
摘要:
A memory cell includes a load transistor pair serving as a high data holding element, a drive transistor pair serving as a low data holding element, and an access transistor pair for accessing the high data holding element or the low data holding element. A high data holding potential corresponding to the source potential of the load transistor pair is set at a value larger than a supply potential, and a low data holding potential corresponding to the source potential of the drive transistor pair is set at a value larger than a ground potential. In a read operation, a source potential control line of a selected memory cell is connected with a ground line through a source line switch.