CN8330 Datasheet, PDF (57/101 Pages) Conexant Systems, Inc – DS3/E3 Framer with 52 Mbps HDLC Controller

CN8330
DS3/E3 Framer with 52 Mbps HDLC Controller
2.0 Functional Description
2.5 Monitor Mode for Stand-Alone Operation
2.5.1 DS3 Monitor Mode Error Outputs
If stand-alone monitor mode is selected by tying the MON/MIC* pin high, then
the CN8330 operates without a microprocessor and the eight address/data pins
(AD[7:0]) of the microprocessor interface become DS3 alarm and error
indication outputs (Note that E3 framing is not available in monitor mode).
Outputs are provided for LOS, OOF, AIS, yellow alarm (X-bit low or A-bit high),
idle code detect, parity errors, LCVs, and frame bit errors. All indications except
LCV and frame bit errors are level indications and can be counted externally on a
per M-frame basis, if desired. The frame error output is a pulse for each error in
the M- or F-bit positions and can drive a counter directly. The LCV output will be
high for every bit position that is an LCV and can be used with the RXCLK
output to facilitate external counting. All indications are active high and can be
used to indicate the presence of the condition without reference to the clock
output. Figure 2-16 illustrates an LCV indication. The LCV indications are
delayed from the pulse inputs due to B3ZS decoding.
Monitor mode is supported only in DS3 mode. Standalone E3 and HDLC
monitor mode is not supported.
Figure 2-16. Monitor Mode Error Indication Timing
DS3CKI
RXPOS
RXNEG
AD[6]/LCV
100441E
Conexant
2-35