Method and apparatus for monitoring internal bus signals by using a reduced image of the internal bus
US6292908A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 19, 1998 |
| Grant date | Sep 18, 2001 |
| Priority date | — |
| Expiry date | Oct 19, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/349
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An apparatus and method for monitoring an internal communication path, i.e. an internal bus, of an integrated circuit is described. The internal bus operates at a particular frequency, f.sub.b. An image of the internal bus is produced, operating at a lower frequency of operations, f.sub.o, which is more amenable to monitoring by test equipment. Signals are received from and driven to the bus using driver/receiver circuitry. The signals may be input-only, output-only, or bi-directional signals. The signals to be monitored are tapped in the driver/receiver circuitry. Depending on the placement of the signal taps in the driver/receiver logic, the signals may be "out-of-phase" with respect to one another. A buffer/align unit processes the signals in order to produce a time delayed version of the signals. The buffer/aliqn unit is used to bring each of the monitored signals back in phase relative to one another. Encoding circuitry encodes the time delayed version of the bus in a manner that produces an image of the bus at the lower frequency of operations, f.sub.o. The encoding circuitry considers the values of the monitored signals over an encoding window, and produces an encoded value …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.