Single-chip microprocessor

摘要

The microprocessor (1) has a unit (8) for supplying a test mode signal for a self-diagnostic test of the internal circuit or unit. A unit on the external output (9, 10) holds the output (9), supplying signals, and, during this, the unit (8) gives the test mode signal, and during this time also, the internal circuit is tested.The equipment includes also a CPU (2) for controlling the process, a ROM (3) for storing the working programs involved and a RAM (4) acting as a system memory but also holding a test module to ensure normal working can be resumed.