Power conservation with a synchronous master-slave serial data bus
US6557063B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 4, 2002 |
| Grant date | Apr 29, 2003 |
| Priority date | — |
| Expiry date | Jun 4, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L1/1803
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A system is described in which the Master can stop its clock and go into a low-power state (for power conservation reasons) at arbitrary times. Before going into the stopped-clock or low-power mode, the Master checks that the serial bus is idle (defined as both Clock and Data lines being “High”). A latch circuit is provided which is active when them aster is in low-power mode. The latch circuit watches for the very first negative-going clock pulse (from the slave), and its configuration is such that when latched, it holds the clock line low. Holding the clock line low prompts the slave to discontinue efforts to send the data. Stated differently, the slave will not conclude that it had successfully sent its data, and this prompts the slave to retain a copy of its data for later resending.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.