System and method for automatic retry of transmit, independent of a host processor, after an underrun occurs in a LAN
US6137804A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 2, 1997 |
| Grant date | Oct 24, 2000 |
| Priority date | — |
| Expiry date | Dec 2, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L12/40195
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In a local area network, a system and a method to detect transmit underruns and retransmit frames between a sending station and a receiving station using a Media Access Control (MAC) device in lieu of a sending processor. The MAC device includes a MAC processor for transmitting data in blocks from a host buffer to a storage device, e.g., RAM for retransmission to the network via a Media Independent Interface (MII) unit. The MAC device includes a transmit logic unit which uses a control word set by the MAC processor to transmit data by frames from the storage device to the network. The transmit logic unit includes pointer control logic to identify the start address of the data and to track the data as read from the storage device to the network. When a transmit underrun occurs, the transmit logic recognizes the condition and resets the pointer logic to the start of the first frame for retransmission to the receiving station. During retransmission, the MAC processor continues to transfer data from the sending system to the storage device which eventually provides sufficient data to overcome the underrun condition. A frame is repeated if a underrun condition continues until the frame …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.