Methods and apparatus for testing multiple-IC devices

摘要

Embodiments include systems (300, 400) that include at least one integrated circuit (IC) (300, 402, 403, 404) and methods for their testing. Each IC (300, 402, 403, 404) includes an input interconnect (340) to receive an input signal, a test enable interconnect (344) to receive a test enable signal, and a controller (320) (e.g., a TAP controller) for performing testing of the integrated circuit based on values in at least one register (330, 332) (values corresponding to the input signal). Each IC also includes an input port (312) and a multiplexer (324) coupled to the first input interconnect (340), the at least one register (330, 332), and the input port (312). The multiplexer (324) is controllable to pass the input signal to the input port (312) in response to non-assertion of the test enable signal, and to pass the input signal to the at least one register (330, 332) in response to assertion of the test enable signal. When the system includes multiple controllers (320, 420, 421, 422), each controller (320, 420, 421, 422) may implement a different opcode-to-instruction mapping.