DS2156
2.1 Block Diagram
Figure 2-1 shows a simplified block diagram featuring the major components of the DS2156. Details are
shown in subsequent figures. About 30 device pins have dual functions depending on the selection of the
backplane, UTOPIA, or TDM. Some of the block diagrams depict a configuration based on the state of
the backplane selection. The block diagram is divided into three functional blocks: LIU, FRAMER, and
BACKPLANE INTERFACE.
Figure 2-1. Block Diagram
CLOCK
CLOCK
ADAPTER
EXTERNAL ACCESS
TO RECEIVE SIGNALS
(TDM BACKPLANE ONLY)
RX
LIU
MUX
HDB3 / B8ZS
SYNC
SINGALING
ALARM DET
HDLCs
TX
LIU
MUX
LIU
EXTERNAL ACCESS
TO TRANSMIT SIGNALS
(TDM BACKPLANE ONLY)
FRAMER
SINGALING
ALARM GEN
HDLCs
CRC GEN
HDB3 / B8ZS
FRAMER
JTAG HOST INTERFACE ESIB
BACKPLANE
CLOCK SYNTH
BACKPLANE
INTERFACE
CIRCUIT
UTOPIA
or
TDM
BACKPLANE
INTERFACE
DS2156
13 of 262