Abstract: Roughly described, a method of powering down a portion of an integrated circuit chip, the portion of the integrated circuit chip comprising a plurality of peripheral circuits, each peripheral circuit being connected to a respective debug unit, the method comprising: prior to power down, extracting from each debug unit configuration information of that debug unit; storing the configuration information of the debug units in a memory on the integrated circuit chip during power down of the portion of the integrated circuit chip; and on power up, restoring the configuration information of each debug unit to that debug unit prior resuming operation of that debug unit and the peripheral circuit connected to that debug unit.

Abstract: Roughly described, a method of restricting access of a debug controller to debug architecture on an integrated circuit chip, the debug architecture comprising an access controller, a plurality of peripheral circuits, and a shared hub, the shared hub being accessible by the access controller and the plurality of peripheral circuits, the method comprising: at the access controller, authenticating the debug controller; at the access controller, following authentication, assigning to the debug controller a set of access rights, the set of access rights granting the debug controller partial access to the debug architecture; and after assigning the set of access rights, allowing the debug controller access to the debug architecture as allowed by the set of access rights.

Abstract: Roughly described, a method of powering down a portion of an integrated circuit chip, the portion of the integrated circuit chip comprising a plurality of peripheral circuits, each peripheral circuit being connected to a respective debug unit, the method comprising: prior to power down, extracting from each debug unit configuration information of that debug unit; storing the configuration information of the debug units in a memory on the integrated circuit chip during power down of the portion of the integrated circuit chip; and on power up, restoring the configuration information of each debug unit to that debug unit prior resuming operation of that debug unit and the peripheral circuit connected to that debug unit.

Abstract: Roughly described, an integrated circuit chip comprises a plurality of peripheral circuits, each peripheral circuit connected to a respective debug unit, the respective debug unit configured to generate debug information of that peripheral circuit; and a plurality of separate stores for receiving debug information, storing debug information, and outputting debug information; wherein in response to a single trigger signal, the debug units are configured to stream their generated debug information to the plurality of separate stores; and wherein each of the plurality of separate stores is configured to receive debug information at a higher stream rate than it outputs debug information.

Abstract: Roughly described, a method of powering down a portion of an integrated circuit chip, the portion of the integrated circuit chip comprising a plurality of peripheral circuits, each peripheral circuit being connected to a respective debug unit, the method comprising: prior to power down, extracting from each debug unit configuration information of that debug unit; storing the configuration information of the debug units in a memory on the integrated circuit chip during power down of the portion of the integrated circuit chip; and on power up, restoring the configuration information of each debug unit to that debug unit prior resuming operation of that debug unit and the peripheral circuit connected to that debug unit.

Abstract: A data processing apparatus, comprising processing circuitry, which in use, generates data and debug circuitry arranged to debug operation of the processing circuitry. The processing circuitry includes bus circuitry arranged to pass data at least one of into and out of the processing apparatus over a communication bus. The debug circuitry comprises monitoring circuitry arranged to monitor the data generated, in use, by the processing circuitry and generate a stream of trace elements. An interface unit is arranged to interface, using the bus circuitry, the trace elements generated by the monitoring circuitry onto the communication bus to be output, in use, from the processing apparatus using the communication bus. The interface unit comprises a controller which is arranged to control operation of the interface unit independently of the operation of the processing circuitry.