Abstract: A measuring light of specific wavelength, which is selectively absorbed by fuel, is transmitted through a measuring passage in a combustion chamber of an engine, to be received by a light receiving element, and intensity of the measuring light of specific wavelength received by the light receiving element is detected.

Abstract: A branch/prefetch judgement portion, in receipt of a branch request signal, sets a cache access mode switch signal to an “H” level. Thus, a cache memory operates in the 1-cycle access mode consuming a large amount of power. In receipt of a prefetch request signal, the branch/prefetch judgement portion sets the cache access mode switch signal to an “L” level. Thus, the cache memory operates in the 2-cycle access mode consuming less power.

Abstract: Controlling of an engine provided with a catalytic converter in an exhaust passage is executed during an idling operation of the engine to heat catalyst in the catalytic converter while permitting the self-ignition combustion mode to be performed in the engine when the catalyst is in a non-active condition, and when the temperature Te of the engine cooling water is higher than a predetermined threshold value Te1, and to allow execution of the self-ignition combustion mode as well as the idling-stop function when the catalyst is in an active condition, and when the temperature Te of the engine cooling water is higher than a predetermined threshold value Te2 that is larger than the predetermined threshold value Te1.

Abstract: A measuring light of specific wavelength, which is selectively absorbed by fuel, is transmitted through a measuring passage in a combustion chamber of an engine, to be received by a light receiving element, and intensity of the measuring light of specific wavelength received by the light receiving element is detected.

Abstract: Controlling of an engine provided with a catalytic converter in an exhaust passage is executed during an idling operation of the engine to heat catalyst in the catalytic converter while permitting the self-ignition combustion mode to be performed in the engine when the catalyst is in a non-active condition, and when the temperature Te of the engine cooling water is higher than a predetermined threshold value Te1, and to allow execution of the self-ignition combustion mode as well as the idling-stop function when the catalyst is in an active condition, and when the temperature Te of the engine cooling water is higher than a predetermined threshold value Te2 that is larger than the predetermined threshold value Te1.

Abstract: A data processing system which executes pipeline processing that decodes a subsequent instruction in an execute phase of a current instruction in response to a clock signal. The data processing system includes a CPU and a mode management block. The CPU supplies an address bus with at least one predetermined address in an execute phase of a clock supply stop instruction. The mode management block produces a clock stop signal if the predetermined address agrees with a self-address assigned to the management block in advance, thereby halting the supply of the clock signal. This makes it possible to solve a problem of a conventional data processing system in that it executes the instruction next to the clock supply stop instruction in spite of execution of the clock supply stop instruction because the clock stop signal is actually output when the clock supply stop instruction shifts from the execute phase to the write back phase, in which case the next instruction proceeds in the execute phase.

Abstract: A synchronous serial data transfer device provides a data control mechanism that sets the level of a data output terminal to a state corresponding to a state data item stored in a serial data state storing mechanism in advance. A clock control mechanism sets the level of a clock output terminal to a clock disable state corresponding to a state data item stored in a clock state storing means in advance.

Abstract: A direct-injection type spark-ignition internal combustion engine comprises a fuel-injection valve whose spray hole is inclined toward a piston crown, while an uppermost line of fuel spray injected through the spray hole is set at a lower level than electrodes of the spark plug and a lowermost line of the fuel spray is in spaced relationship with a cylinder inner wall close to the spray hole. The piston crown is formed with a recessed portion and a raised flat-surface portion to define a ridge line as an intersecting line between them. The ridge line is offset from a center axis of the cylinder by a predetermined distance toward the exhaust-valve port side. Preferably, a spray angle between the uppermost and lowermost lines is set within a predetermined angle range of 70.degree..+-.20.degree..

Abstract: An exhaust system for internal combustion engines includes at least two exhaust passages, each passage communicated with at least one branch exhaust passage of an exhaust manifold communicating exhaust ports of a multiple-cylinder engine, and a confluent exhaust passage disposed downstream of said at least two exhaust passages, said confluent exhaust passage including a confluent point for converging downstream ends of said at least two exhaust passages. The exhaust system also includes a communication passage substantially parallel with the at least two exhaust passages and a valve disposed in the communication passage, for allowing a portion of exhaust gas flow to bypass said confluent point only when the engine is within a predetermined high engine revolution range.

Abstract: To smoothly introduce intake air or mixture through at least one intake valve and exhaust combustion gas through at least exhaust valve, an intake side conical wall surface is formed in an inner wall of the cylinder head in smooth continuous connection with a conical surface formed at an end of the intake valve seat, and an exhaust side conical wall surface is also formed in the inner wall of the cylinder head in smooth continuous connection with a conical surface formed at an end surface of the exhaust valve seat. It is preferable not to allow liquid fuel introduced through the intake to flow directly toward an ignition plug provided at the center of the cylinder, but to allow the introduced liquid fuel to flow directly toward the exhaust port along a flat surface, recess, groove, guide surface, etc. formed around the ignition plug for prevention of misfiring.