Abstract: A debug program is decoded in a command decoder to generate a debug start signal. Then, a signal processing operation is halted and a state of an internal circuit is latched and read to be supplied to an external circuit. When the reading of the state starts, a signal-processing continuation signal is generated, so that the signal processing operation is restored to be continued. Therefore, the debug program can be inserted to a program memory at plural addresses without braking the signal processing operation.

Abstract: A fiber-reinforced ceramic green body containing fine ceramic fibers uniformly dispersed in a ceramic matrix. The green body is composed of 50 weight % or more of a ceramic main component such as Si.sub.3 N.sub.4 and 50 weight % or less of at least one ceramic additive such as Al.sub.2 O.sub.3 and Y.sub.2 O.sub.3, at least part of one or both of said ceramic main component and said ceramic additive being in the form of fine fibers. This green body is produced by a slip casting method.

Abstract: In a boiler or an industrial furnace, a temperature detecting sensor is mounted at the heat absorbing side of a heat pipe of a waste heat recovery device which is disposed in part of the path of exhaust gas. With an output signal of the temperature detecting sensor, a flow rate control valve is controlled, and a liquid discharging shield is utilized to maintain the flow rate of the liquid to be supplied in correspondence with the flow rate of the liquid to be discharged. The effective area of the heat pipes coming in contact with the liquid is varied to maintain the temperature at a heat absorbing side higher than the dew point of sulfur oxide, thus preventing the heat pipes from corrosion, exhaust ducts and so on, and allowing heat absorbing operation to be performed in accordance with the exhaust gas discharge temperature.