Pass-Through Mode - Interphase 4538 Hardware Reference Manual

TDM Bus Configurations

Pass-Through Mode

In this mode, PA(7) = SWMODE_N = 1 and PA(0) = COMCLK_N = 0.
Pass through is possible from framer 1 to framer 2 and vice versa and from framer 3 to
framer 4 and vice versa. The four framers have the same rhythm (COMCLK_N = 0).
In framer 1 to framer 2 pass-through mode, the first framer is tied to the network in LT
mode. Data received from this framer goes to TDMa1 and to the second framer, which is in
NT mode, by using TDMc1 in Echo Mode, so that it can be connected to another adapter
configured as a line Termination (LT) circuit. Data received from framer 2 is combined
with data from TDMa1 by using TDMd1 in Echo Mode, and sent by framer 1; TDMd1_TX
and TDMa1_TX must be configured as open drain ports. TDMb1 is not used and must
be configured as input. Framer 2 to framer 1 pass-through description is symmetrical. The
same description applies to framer 3 and framer 4.
Figure 1-18,
this mode. Only the framer 1 to framer 2 and framer 3 to framer 4 pass through is described.
Grey lines indicate unused connections.
Table 1-33. TDM and Synchronization Signals in Pass Through Mode
52
Figure 1-19, Figure 1-20 and Figure 1-21show the specific implementation of
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