Racal Data Communications Inc.

Juan E Farias

Raul F Fernandez

Donald Lee Wray

Edward J Sackman, Iii

Donald C O'Connor

Dale R Jenkins

Jon S Miller

George A Clarke

Leroy D Young

An apparatus for controlling access to a time division multiplexed (TDM) bus includes a frame address register having a plurality of storage registers for storing a plurality of frame addresses designated for use in communicating over said TDM bus. A frame address latch stores a current frame address. A frame comparator, coupled to the frame address register and the frame address latch, compares the designated frame addresses with the current frame address and produces a first signal indicative of the storage register containing a frame address matching the current frame address. A time slot register has a plurality of storage registers for storing a time slot number designated for use in communicating over said TDM bus. A time slot generator generates a current time slot number. A time slot comparator, coupled to the time slot register and the time slot generator compares the designated time slot number with the current time slot number and produces a second signal indicative of the storage register containing a slot number matching the current time slot number. A token generator, coupled to the frame comparator and the time slot comparator receives the first and second signals and generates a token work unique to the first and second signals. A data transfer circuit transfers a data word to or from the TDM bus responsive to the token word.

TDM bus controller

A method for changing the data transmission rates in a synchronous data communication system including a first modem and a second modem coupled together through a transmission channel, the transmission channel including a first path for transmissions from the first modem to the second modem and a second path for transmission from the second modem to the first modem, includes the steps of determining, at the first modem, that the second path of the transmission channel is adequately high in quality to support an increase in transmission rate. Next it is determined, at the second modem, that the first path of the transmission channel is adequately high in quality to support an increase in transmission rate. A training sequence is then transmitted at an increased transmission rate from the second modem to the first modem. Next, a training sequence is transmitted at the increased transmission rate from the first modem to the second modem.

Data modem with adaptive synchronized speed change

Growing community of inventors

Sunrise, FL, United States of America

Juan E Farias