Integrated circuit scanning apparatus having scanning data lines for connecting selected data locations to an I/O terminal
US4752907A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1986 |
| Grant date | Jun 21, 1988 |
| Priority date | — |
| Expiry date | Jun 30, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/2268
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A scan apparatus provides an interface and control signals between a secondary computer and data locations in a host computer. The scan apparatus functions independently of the normal operation of the host computer. Scan-out is performed transparently to the operation of the host computer. The host computer is constructed using circuits on semiconductor chips. The semiconductor chips are organized in blocks. Chips within each block include scan apparatus which controls the scan operations in connection with that chip. The scan apparatus in each chip is connected through two I/O pins to a clock line and to a bidirectional scan data line. The scan apparatus on each chip includes a multimode sequencer so that each chip in each block can be independently performing scan sequences. The block scan apparatus and the secondary computer perform the functions of requesting a scan sequence for transmitting the scan data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.