Apparatus and method for determining a presence of a stored data

Details Apparatus and method for determining a presence of a stored data Apparatus and method for determining a presence of a stored data

1997-12-18

2000-10-03

Olms, Douglas W.

Multiplex communications

Pathfinding or routing

Store and forward

370445, 710 52, 714719, 375354, H04L 1254, H04L 12413

Patent

active

061283088

ABSTRACT:
A network interface device includes a random access memory used as a transmit and receive buffer for transmission and reception of data frames between a host computer bus and a packet switched network. The network interface device includes read and write controllers for each of the transmit and receive buffers, where each write controller operates in a clock domain separate from the corresponding read controller. The memory management unit also includes a synchronization circuit that controls arbitration for accessing the random access memory between the read and write controllers. The synchronization circuit determines the presence of a stored frame in the random access memory by asynchronously comparing write counter and read counter values stored in gray code counters, where each counter is configured for changing a single bit of a counter value in response to an increment signal. Use of gray code counters enables asynchronous comparisons to be made between the two counter values, independent of the host computer bus clock domain and the network clock domain.

REFERENCES:
patent: 5426756 (1995-06-01), Shyi et al.
patent: 5594702 (1997-01-01), Wakeman et al.
patent: 5898889 (1999-04-01), Davis et al.
patent: 5905766 (1999-05-01), Nguyen
patent: 5951635 (1999-09-01), Kamgar
patent: 5974518 (1999-10-01), Nogradi
patent: 5978868 (1999-11-01), Maas
Stallings, Local and Metropolitan Area Networks, fifth edition, pp.: 32-33, 38, 40, 131, 186, 1997.

Affiliated with

Also associated with

Rating

Apparatus and method for determining a presence of a stored data does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Apparatus and method for determining a presence of a stored data, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and method for determining a presence of a stored data will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-202388