SEMICONDUCTOR INTEGRATED CIRCUIT

摘要

PURPOSE:To attain a function test of a microcomputer even in an initial state of an EPROM by setting a prescribed function in a default state based on the output of a flag circuit using an EPROM similar to a prescribed function control EPROM. CONSTITUTION:In a 1-chip microcomputer of a semiconductor device containing a prescribed function control EPROM 52 provided in a switch circuit 53, an EPROM 20 similar to the EPROM 52 is used to a flag circuit 11 and a priority setting circuit 32 is kept in an inhibition state as long as the outputs S1 - S6 of the circuit 33 are all set at H with the EPROM 52 kept in an initial state. Meanwhile the output of a default setting circuit 12 is selected via a selection circuit 14 where the output passed through an inverter 16 of the circuit 11 is formed via an OR circuit. Then a prescribed function is set in a default state, and the output selected by the circuit 14 is supplied to a vector address generating circuit 35 via the gate circuits 15a - 15c. Thus the function test is attained for the 1-chip microcomputer and a burn-in test is also attained.