# US 8,543,875 B2 · Moving third tap controller from exit2-DR state to pause-DR state

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 8,543,875 B2
- Document ID: US8543875B2
- Status: Granted
- Kind: B2
- Application number: 13/680,519
- Filed: 2012-11-19
- Published: 2013-03-28
- Granted: 2013-09-24
- Earliest claimed: 2007-06-07
- Assignees: Texas Instruments Incorporated
- Applicants: Texas Instruments Incorporated
- Inventors: Gary L. Swoboda
- Web page: https://patentgrep.com/patent/US8543875B2

## CPC

- G01R 31/318544: {Scanning methods, algorithms and patterns (G01R31/3183 takes precedence)}
- G01R 31/318558: {Addressing or selecting of subparts of the device under test}
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)

## Abstract

A method implemented to test a plurality of components coupled in a star configuration, each component having a test access port (TAP) controller. The method comprises performing a capture phase of a scan operation on all of the TAP controllers in the star configuration and sequentially selecting one of the TAP controllers at a time to perform a shift state. When all of the TAP controllers have been sequentially selected to perform the shift phase, the method further comprises selecting all of the TAP controllers to perform an update phase.

## Claims

### Claim 1

A process of testing target systems connected in a star configuration, each target system having a test access port controller, comprising:
A. moving all of the TAP controllers from a RunTest/Idle state, through a Capture-DR state and an Exit1-DR state into a Pause-DR state without traversing a Shift-DR state;
B. selecting a first TAP controller with first encoded bits on a TDI input to each target system;
C. moving only the first TAP controller through an Exit2-DR state, a Shift-DR state, the Exit1-DR state, and back to the Pause-DR state;
D. de-selecting the first TAP controller and selecting a second TAP controller with second encoded bits on the TDI input to each target system;
E. moving only the second TAP controller through an Exit2-DR state, a Shift-DR state, the Exit1-DR state, and back to the Pause-DR state;
F. de-selecting the second TAP controller and selecting a third TAP controller with third encoded bits on the TDI input to each target system;
G. moving only the third TAP controller through an Exit2-DR state, a Shift-DR state, the Exit1-DR state, and back to the Pause-DR state; and
H. selecting all of the TAP controllers with encoded bits on the TDI input to each target system and moving all of the TAP controllers from the Pause-DR state to an Update-DR state.

### Claim 2 (depends on 1)

The process of claim 1 in which selecting one of the TAP controllers includes generating a controller address unique to the TAP controller.

### Claim 3 (depends on 1)

The process of claim 1 in which selecting one of the TAP controllers includes providing a controller address to all of the TAP controllers, the controller address being valid for only one of the TAP controllers receiving the address.

### Claim 4 (depends on 1)

The process of claim 1 including assigning a unique address or identifier to each TAP controller from which each TAP controller is then selected.