AN ELECTRONIC STREAM PROCESSING CIRCUIT WITH TEST ACCESS

摘要

An electronic signal processing circuit contains a chain of stream processing circuits (12a-d). Linking multiplexing circuits (16a-c), link respective pairs of stream processing circuits (12a-d). Each linking multiplexing circuit (16a-c) is individually switchable to a normal mode and to a replacement mode. A linking multiplexing circuit (16a­ c), when in the normal mode, provides a continuous connection for passing a first stream of samples values between the stream processing circuits (12a-d) in the respective pair. A shareable communication structure (14a-c) is coupled to the linking multiplexing circuits (I 6a-c). Each linking multiplexing circuit (16a-c), when in the replacement mode, provides a continuous connection for supplying successive sample values from a second stream from the communication structure (14a-c) to a receiving one of the stream processing circuits (12a-d) in the respective pair of the linking multiplexing circuit (16a-c). A control circuit (18) keeps a selectable one of the multiplexing circuits (I6a-c) in the replacement mode so that the selectable one of the linking multiplexing circuits (16a-c) passes a stream of successive sample from the second stream to the receiving one of the processing circuits in the respective pair of linking multiplexing circuit (16a-c), while keeping at least part of the other linking multiplexing circuits (I6a-c) in the normal mode.