Abstract: An integrated circuit comprising a main section/processor and a subsection/subprocessor for debugging the main section is provided with hardware modules coupled via a subbus to said subprocessor and coupled to different parts of said main section, for debugging more directly. The hardware modules comprise a shiftregister coupled to a chain unit and a clock controller coupled to a clock generator for scanning purposes, a scan controller coupled to said chain unit for selection scanning options, a breakpoint controller coupled to said chain unit for interrupting said scanning, and/or a programmable register coupled to dedicated hardware for tracing purposes. An access module is coupled to an interface for communication with the outside world and is further coupled to an access memory. A subprocessor memory stores amendable/replacable software for controlling said subsection and said debugging as well as a transmission of debugging results via said access module to an external debugger.

Abstract: To test the processing of a data frame processing unit (FPU) which, in a normal working mode, processes input data frames applied to a data frame input (FI) thereof, the data frame processing unit (FPU) is brought in a test mode. Therefore, an active test signal is applied to a test mode control input (TCI) of this data frame processing unit (FPU). When brought in the test mode, the frame counters of the data frame processing unit (FPU) have lower limits and test data frames with smaller dimensions than the input data frames applied to the data frame input (FI).

Abstract: In a digital sigma-delta modulator with multi-phase operations by time-sharing including an adder to produce multiple integration, an arrangement includes switching circuitry for alternately establishing one of: a connection between a first input of the adder and an input of the modulator; and connections between the adder output and the first input of the adder by way of a first integration delay circuit, and the adder output and a second input of the adder by way of a second delay circuit.