Abstract: In a first step, basic components including (A) 100 parts by weight of an organopolysiloxane gum, (B) 5-100 parts by weight of a reinforcing silica filler, and (C) 0.1-30 parts by weight of a processing aid are fed batchwise to a closed mixer for mixing them at a temperature of room temperature to 150.degree. C. In a second step, the mixture is fed into a kneader/mixer for heat treating at a temperature of 150-250.degree. C. The first step achieves quick dispersion and cooperates with the second step to form a heat-curable silicone rubber compound in an efficient manner.

Abstract: In a programmable logic device having a memory circuit for storing circuit configuration data and a logic gate block for realizing a logic circuit desired by a user on the basis of the circuit configuration data written into the memory circuit, a switching circuit is provided for controlling at least a part of a circuit for writing the circuit configuration data into the memory circuit so as to be utilized as a part of the logic circuit desired by the user after the circuit configuration.