Impedance updating apparatus of termination circuit and impedance updating method thereof
US6556038B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 20, 2001 |
| Grant date | Apr 29, 2003 |
| Priority date | — |
| Expiry date | Aug 20, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/0298
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An impedance updating apparatus includes a terminator circuit for receiving and terminating an external input signal, the terminator circuit having an up-terminator and a down-terminator; and an update controller for separately controlling the up-terminator and the down-terminator based on the level of the external input signal. The update controller includes at least one latch for latching impedance codes of a programmable impedance controller, the impedance codes being used for controlling transistors in the up-terminator and down-terminator. The update controller performs updating impedance of the up-terminator, or down-terminator when an up-update enable signal or a down-update enable signal and a level of the external input signal correspond to a predetermined condition. And the update controller performs updating impedance of the up-terminator, or down-terminator in response to a level of the external input signal during set-up or hold time only. An impedance updating method of termination circuit having up/down terminators and a separate update controller for detecting terminator through which minimum current flows in response to level of an external input signal is also pro…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.