| 摘要 |
PURPOSE:To facilitate an easy check of an external terminal for input of a test instruction given from outside by controlling the writing/reading of an instruction given to an instruction RAM according to the control signal given from a test mode setting register provided inside a data processor or from outside. CONSTITUTION:An instruction for test of external terminals R0-Ri is supplied during the input of a test instruction, and a writing operation is carried out to a test mode register within a test control circuit TCC to set the test mode of those external terminals. Then a multiplexer MPX is switched to cut off the output of instructions to an instruction decoder ID from an ROM and terminals R0-Ri. In stead the instructions of one or several words which are held by instruction I- RAM is repetitively read out and supplied to the decoder ID and executed. Then the test is given to terminals R0-Ri which are used for input of test instructions. |
