XRT4500 Datasheet, PDF (42/99 Pages) Exar Corporation – MULTIPROTOCOL SERIAL NETWORK INTERFACE IC

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XRT4500
MULTIPROTOCOL SERIAL NETWORK INTERFACE IC
REV. 1.0.7
1.2 THE SYSTEM ARCHITECTURE
The XRT4500 contains the following functional
blocks.
• The High-Speed Transceiver Block
• The Handshaking/Control Transceiver Block
• The Diagnostic Operation Indicator Transceiver
Block
• The Control Block
Block Diagrams are located on page 1 and 2. The
figures illustrate how the eight receivers and transmitters
in the XRT4500 are grouped into the “High-Speed
Transceiver” Block, the “Handshaking/Control Trans-
ceiver” Block and the “Diagnostic Operation Indicator
Transceiver” Block.
The “Control” block permits the user to implement the
following configuration options in the XRT4500.
• Select which Communication Interface Mode the
XRT4500 will operate in. (RS-252, V.36, etc.)
• Configure the XRT4500 into either the DTE or the
DCE Mode.
• Configure the XRT4500 to operate in a “Loop-back”
Mode.
• Enable the “Echo-Clock” Mode.
• Configure the XRT4500 into the “Latch” Mode.
• Configure the XRT4500 into the “Register” Mode.
• Configure the XRT4500 into either the “2-Clock” or
the “3-Clock” Mode.
• Enable the “Internal Oscillator”, in order to support
“Stand-Alone DTE Diagnostic Operation.
• Invert the TXC Clock signal (for DCE Application) or
the RXC Clock signal (for DTE Applications).
• Invert the TXD signal (for DTE Applications) or the
RXD signal (for DCE Applications).
• Enable the X.21 mode.
A more detailed discussion of the “Control” Block can
be found in Section 1.2.4.
Figure 12, Figure 13, Figure 14, and Figure 15 are a
set of functional block diagrams that give more de-
tailed information about the four functional blocks
shown in the top-level diagram. Figure 12 presents
detailed information on the “High-Speed Transceiver”
block. Figure 13 presents detailed information about
the “Handshaking/Control Transceiver” block.
Figure 14 presents detailed information about the “Di-
agnostic Operation Indicator Transceiver” Block. Fi-
nally, Figure 15 presents some detailed information
about the “Control” Block.
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