Rate control of channels on a time division multiplex bus

Abstract

Information flow in the form of individual channels of digital data across a time division multiplex (TDM) bus is controlled when the bandwidth b.sub.c of an individual channel may not be integrally related to the bandwidth b.sub.t of individual time slots of the TDM bus. A channel is assigned to a selected number m of TDM bus time slots, where m=n and the relationship between b.sub.c and b.sub.t is given by the expression (n-1)b.sub.t <b.sub.c .mu.nb.sub.t. Sequential bytes of data from the channel are transmitted during data byte opportunities in the channel's selected time slots. A validity identification signal is generated for each data byte transfer opportunity in the selected time slots, and a predetermined binary state is transmitted substantially simultaneously with each data byte transfer opportunity. A VALID signal is transmitted, independently of the TDM bus, substantially simultaneously with each data byte transfer opportunity filled by the channel. To permit selected bandwidth in the reverse direction to be controlled over a bidirectional TDM bus, a separate bandwidth request signal may also be transmitted, substantially simultaneously with data byte transfer opportunities in the forward direction but also independently of the TDM bus.