Abstract: Disclosed is an output interface for an integrated circuit permitting input and output pads to selectively receive binary data elements or electrical signals from multiple sources. The output interface contains a storage mechanism that stores the N binary information elements present on N internal lines of the integrated circuit and a multiplexer that presents the binary information in packets of K bits to a connection mechanism. Upon direction from a control mechanism, an insulation mechanism disconnects the pads from internal circuits on the chip, the connection mechanism connects the pads with the multiplexer, and the multiplexer sequentially makes the binary information available in packets of K bits to the K pads.

Abstract: The integrated circuit comprises a central processing unit, a program memory containing a program of instructions connected to the central processing unit by an address bus, a data bus and lines giving control signals for read and write access to this memory, the instructions being carried out by the central processing unit, and at least one data memory connected to the central processing unit by an address bus, a data bus and lines giving control signals for read and write access to this memory. The circuit comprises breaking means enabling the defining of a combination of conditions pertaining to the values present on two of the buses of the memories and to the values of the control signals for access to at least one of these memories, and halting the performance of the instructions if these conditions are verified. The disclosed device is especially valuable for testing an application program of the integrated circuit.

Abstract: A method and apparatus to test the running of a program of instructions encoded on one or more words, carried out by an integrated circuit, the program being contained in a memory connected to a central processing unit by means of an instruction address bus. A stack of registers is formed and this stack is connected to the instruction address bus in such a way that the address of the first word of each instruction carried out is stored in the stack at the time when it is carried out.