Method and apparatus for detecting impending overflow and/or underrun of elasticity buffer
US4945548A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 14, 1988 |
| Grant date | Jul 31, 1990 |
| Priority date | — |
| Expiry date | Oct 14, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2007/045
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A parallel asynchronous elasticity buffer. Selection of the address of a storage element for writing or reading of data is provided by asynchronous input and output pointers implemented using circular gray code counters. The buffer is initialized once during transmission of each frame of data so that the pointers do not select the same storage element for writing and reading at the same time. Write overflow or read underrun of a storage element is detected before any data corruption can occur by comparing the input and output pointers. An error condition is detected if the input and output pointers overlap for a threshold period, which can be shorter than the period required for writing or reading of a multibit data unit to or from the buffer. The overlap time period is determined by comparing the pointers at one or more sampling times corresponding to selected phases of a clock signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.