Patent ID: 7337378

Claim:
A semiconductor integrated circuit comprising a first memory, a second memory with a test instruction code stored therein, and a functional unit, said semiconductor integrated circuit further comprising: a mode selecting unit for selecting a burn-in test mode for carrying out a burn-in test and for outputting predetermined control signals when the burn-in test modes selected; wherein said burn-in test comprises a first burn-in test and a second burn-in test, and the first burn-in test and the second burn-in test are executed independently to each other according to the predetermined control signals from said mode selecting unit; said first burn-in test performing a reading operation from said first memory with predetermined test data written therein, and said second burn-in test reading out the instruction code in said second memory, for execution and operating said functional unit; wherein the predetermined control signals comprise a first control signal and a second control signal, and said mode selecting unit outputs the first control signal at a first level when a normal mode for reading out a content stored in said first memory for execution is selected, and when the burn-in test mode is selected, said mode selecting unit outputs the first control signal at a second level and also outputs the second control signal; wherein said mode selecting unit switches a level of the second control signal with the first control signal at the second level input to said functional unit, thereby alternately switching the first burn-in test and the second burn-in test, for execution; and wherein said functional unit comprises: a first selection circuit for switching a destination of output of the content in said first memory according to the level of the second control signal; and a second selection circuit for switching a source of an input between said first selection circuit and said second memory according to the level of the first control signal, and outputting the input to an instruction register; and said semiconductor integrated circuit is so configured that switching between the normal mode for reading out the content stored in said first memory for execution and the burn-in test mode can be performed according to the first control signal, and at a time of the burn-in test mode, switching between the first burn-in test and the second burn-in test can be performed according to the level of the second control signal.