Circuit and method of indicating data hold-time
US5548285A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 18, 1994 |
| Grant date | Aug 20, 1996 |
| Priority date | — |
| Expiry date | Jul 18, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K5/1534
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A parallel to serial converter (10) uses a data hold-time indicator (22) to indirectly observe the timing relationship of the data and clock applied to a data register (14) embedded within an integrated circuit. The incoming data word is converted from CMOS to ECL logic levels (12) and applied to the data register. The register holds data for a multiplexer (16) that rotates through the output data from the register for providing a serial data output signal. A flipflop circuit (18) clocks the serial data output signal. The data hold-time indicator circuit monitors one register input and generates a recurring pulse having a width that reflects the data hold-time at the embedded register. By indirectly observing the timing relationship, the externally sourced data timing can be calibrated to meet the setup and hold-time requirements of the data register.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.