Scan interface with TDM feature for permitting signal overlay
AssigneeTexas Instruments Incorporated
InventorGary L. Swoboda
Life of this patent
Estimating the term…
Abstract
A scan interface that includes control signals (TRST, TMS, TCK) and data signals (TDI, TDO) normally carried by respective signal paths of the scan interface can be used to carry signals other than signals of the scan interface. A first signal (TMS) and a second signal (TDO) can be time division multiplexed on the signal path that normally carries one of the signals, thereby freeing the signal path that carries the other of the signals to carry a signal other than a signal of the scan interface.
Claims20
A method of supporting communication with a scan interface which utilizes a plurality of signals, each of the signals normally carried by respective signal paths of the scan interface, comprising:
- providing a first signal associated with the scan interface;
- providing a second signal associated with the scan interface;
- and
- time division multiplexing the first and second signals on a single signal path.
A scan adaptor apparatus, comprising:
- a first communication port for communicating with an emulator via first and second signals associated with a scan interface and time division multiplexed on a single signal path of said first communication port;
- a second communication port for coupling to the scan interface;
- and
- an adaptor coupled between said first and second communication ports for receiving said time division multiplexed first and second signals and providing in response thereto said first and second signals on respective signal paths of said second communication port.
An integrated circuit, comprising:
- a data processing core;
- a scan interface coupled to said data processing core for permitting scan communications therewith;
- and
- a scan interface adaptor including a first communication port for communicating with an emulator via first and second signals associated with said scan interface and time division multiplexed on a single signal path of said first communication port, a second communication port coupled to the scan interface, and an adaptor coupled between said first and second communication ports for receiving said time division multiplexed first and second signals and providing in response thereto said first and second signals on respective signal paths of said second communication port.
Dependencies are inferred from the claim text.