Debug apparatus and methods for dynamically switching power domains

摘要

Methods and apparatus are provided that facilitate debugging operations for components in dynamic power domains. In an embodiment, an integrated circuit includes hardware sectors associated with observability circuits served by a debug data bus of a debug circuit. A controlled sector residing in a dynamically-controlled power domain may be turned off while the power domain of another sector remains on. To continue to have debug observability all the way through and after these power events, a debug data register is configured to provide data, such as configuration and/or programming data, to the observability circuit of the controlled sector via the debug data bus. A shadow register is configured to capture the data provided to the controlled sector's observability circuit. The shadow register data is used upon restoring power to the controlled sector to restore the controlled sector's observability circuit to a state when the controlled sector was previously powered on.

主权项

1. An integrated circuit (IC) comprising:
a plurality of hardware sectors, each hardware sector associated with a debug observability circuit that is served by a debug data bus of a debug circuit, wherein the plurality of hardware sectors includes one or more steady state sectors residing in an always on power domain that remains on whenever the debug circuit is operable; the plurality of hardware sectors including a controlled sector residing in a dynamically-controlled power domain that may be turned off while the power domain of another sector remains on; a debug data register configured to provide data to the debug observability circuit of the controlled sector via the debug data bus; a shadow register configured to receive and store the data provided to the debug observability circuit of the controlled sector; and control circuitry configured to utilize the data stored in the shadow register upon a restoration of power to the controlled sector to restore the debug observability circuit associated with the controlled sector to a state reflective of its state when the controlled sector was previously powered on.