摘要 |
A circuit arrangement utilizes a common bus for functional operations of logic circuits and for scan testing the logic circuits. In one embodiment, input/output ports and scan test ports of the logic circuits are switchably coupled to a bus. For functionally testing the logic circuits, a predetermined command transmitted over the bus causes the scan test ports to be coupled to the bus and the input/output ports to be decoupled from the bus. Test data may then be transmitted to and from the logic circuits via the bus. When testing is complete, a second predetermined command transmitted over the bus causes the scan test ports to be decoupled from the bus and the input/output ports to be coupled to the bus. |