IC with state machine controlled linking module
US6804725B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 22, 2001 |
| Grant date | Oct 12, 2004 |
| Priority date | — |
| Expiry date | May 26, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/318572
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A TAP linking module provides for control and access of plural TAPs on an IC through one set of JTAG signal pins. The IC includes plural circuit modules, each with its own TAP, and boundary scan registers connected to an additional TAP. All the TAPs and the linking module have their TDI, TMS and TCK inputs connected to one set of input pins on the integrated circuit. The TDO outputs of all the TAPs and linking module are connected to the TDO pin through a multiplexer. A special instruction scanned into an enabled TAP produces a select signal to the linking module. This disables the enabled TAP and causes the linking module to be the scan path between the TDI and TDO pins. Selection data scanned into the linking module disables the linking module and enables a TAP to be connected between the TDI and TDO pins.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.