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United States Patent  [ii] Patent Number: 5,615,211
Santore et al.  Date of Patent: Mar. 25, 1997
 TIME DIVISION MULTIPLEXED
BACKPLANE WITH PACKET MODE
 Inventors: Peter M. Santore, Cheshire; John M.
O'Neil, Jr., Litchfield, both of Conn.
 Assignee: General DataComm, Inc., Middlebury, Conn.
 Appl. No.: 532,888
 Filed: Sep. 22,1995
 Int. CI.6 H04L 12/56
 U.S. CI 370/419; 370/461; 370/471
 Field of Search 370/60, 60.1, 61,
370/94.1, 94.2, 94.3, 95.1, 95.3, 95.2, 58.1, 58.2, 58.3, 77, 85.1, 85.2, 85.3
 References Cited
U.S. PATENT DOCUMENTS 4,569,042 2/1986 Larson 370/60
Primary Examiner—Douglas W. Olms
Assistant Examiner—Dang Ton
Attorney, Agent, or Firm—David P. Gordon
An integrated TDM-based/packet-based telecommunications backplane system includes a multi-bit backplane bus, a plurality of TDM data modules and packet based data modules coupled to the backplane bus, and a frame controller coupled to the bus which generates a frame by preassigning a first plurality of timeslots of a frame for the fixed rate TDM traffic, and allotting the remainder of the frame timeslots as a pool for packet-based traffic. The TDM data modules, which can include bit, and byte or nibble mode modules, place data on the backplane bus in their allotted time slots. The packet-based data modules contend for the pooled timeslots by raising a request on a "request" thread of the backplane bus when the packet module has a packet to send, and dropping the request and raising a busy flag on the "busy" thread while sending a data packet. In order to insure that only one packet-based data module will attempt to raise the request flag at a given time, the pooled timeslots are divided among the packet data sources for purposes of raising the request flag only. Thus, only one packet-based data module can raise its request flag during a given timeslot of the pool; although when sending data, the packet-based data module can send during all timeslots of the pool.