Renesas Technology Corp.

Other

Hitachi, Ltd.

Atsuhiro Hayashi

Hiroshi Toyoshima

Takemi Negishi

Yasuhiko Takahashi

Satoshi Aoyama

Akira Matsumoto

Takashi Uehara

Kazuhisa Suzuki

Daisuke Hamano

An eye-opening margin measurement method for a high-speed serial data reception circuit which uses a circuit for eye-opening margin measurement involving operation of a clock data recovery circuit without fixing the clock phase. In this method, an error acceleration test can also be made on received data by giving an offset pulse signal to phase information to add a jitter component. The method uses a semiconductor integrated circuit device which includes a serializer/deserializer circuit (SerDes) for receiving serial data and a reference serializer/deserializer circuit (Ref_SerDes) for receiving an accompanying clock signal. The SerDes circuit converts received serial data into parallel data through a recovery clock whose phase is controlled using phase control signal P_CS generated by the Ref_SerDes circuit. An offset pulse signal Offset_Pulse from the pulse-forming circuit is applied to the phase control signal P_CS to make eye-opening margin measurement.

Semiconductor integrated circuit device and method for evaluating an eye-opening margin

The present invention provides a semiconductor integrated circuit that can perform impedance control and slew rate control independently of each other and simplify the structure of a control circuit. An output circuit comprising plural output MOSFETs connected in parallel is used, from among the plural output MOSFETs, the number of output MOSFETS to be turned on is selected by a first control means to control output impedance, and slew rate is controlled by a second control means controlling a drive signal of the output MOSFETs to be turned on.

Semiconductor integrated circuit controlling output impedance and slew rate

A plurality of sets of circuits are provided, each of which generates an impedance code through the use of an impedance control circuit in association with a resistive element connected to an external terminal, and each of which varies the impedance in accordance with such an impedance code. The impedance control circuit includes an impedance comparator which is formed equivalently to the resistive element and the plurality of sets of circuits, and which performs an impedance comparison with each of a plurality of replica circuits to form an up signal that increases the impedance and a down signal that decreases the impedance. Counters are provided adjacent to the individuals of the plurality of sets of circuits to thereby generate the impedance codes in response to the up signal and the down signal.

Semiconductor integrated circuit device

A semiconductor integrated circuit device, which is intended to prevent the characteristic degradation, includes multiple limiter circuits which are laid out by being scattered across a semiconductor substrate to produce an internal power voltage of a certain voltage level. Each limiter circuit is laid out so as to have its transistor formation area located just beneath the formation area of a bump electrode which puts in an externally supplied power voltage. The scattered layout of limiter circuits avoids the concentration of current to one limiter circuit and alleviates the harmful heat-up of the limiter circuits and their periphery. The shorter wiring length from the bump electrode to the transistor results in a smaller wiring resistance, alleviating the power voltage drop on the wiring.

Semiconductor integrated circuit device with a plurality of limiter circuits

Growing community of inventors

Akisima, Japan

Atsuhiro Hayashi