Motorola MPC8260 User Manual

14-4

MOTOROLA

The TSA implements both internal route selection and time-division multiplexing (TDM)
for multiplexed serial channels. The TSA supports the serial bus rate and format for most
standard TDM buses, including T1 and E1 highways, pulse-code modulation (PCM)
highway, and the ISDN buses in both basic and primary rates. The two popular ISDN basic
rate buses (interchip digital link (IDL) and general-circuit interface (GCI), also known as
IOM-2) are supported. 

Because each SI supports four TDMs, it is possible to simultaneously support a
combination of up to eight T1 or E1 lines, and basic rate or primary rate ISDN channels.

The TDMa channel can support E3 or DS-3 rates as a clear channel in either a parallel-
nibble or serial interface.

TSA programming is independent of the protocol used. The serial controllers can be
programmed for any synchronous protocol without affecting TSA programming. The TSA
simply routes programmed portions of the received data frame from the TDM pins to the
target controller, while the target controller handles the received data in the actual protocol.

In its simplest mode, the TSA identiÞes the frame using one sync pulse and one clock signal
provided externally by the user. This can be enhanced to allow independent routing of the
receive and transmit data on the TDM. Additionally, the deÞnition of a time-slot need not
be limited to 8 bits or even to a single contiguous position within the frame. Finally, the user
can provide separate receive and transmit syncs as well as clocks. Figure 14-2 shows
example TSA conÞgurations ranging from the simplest to the most complex.