IDT82P2821 Datasheet, PDF (64/151 Pages) Integrated Device Technology – 21(+1) Channel High-Density T1/E1/J1 Line Interface Unit

IDT82P2821
Recovered clock of one
of the 22 channels
21(+1) CHANNEL HIGH-DENSITY T1/E1/J1 LINE INTERFACE UNIT
CLKB input
JA_BYPAS = 1 ?
No
Clock is derived from the
output of RJA
Yes
Clock is derived from the output
of Rx Clock & Data Recovery
selected by REFB[4:0]
Output on REFB
Figure-41 REFB Output Options in Normal Operation
In LLOS condition.
FS_BYPAS = 1 ?
Yes
No
Pass through a
Frequency Synthesizer.
FREE = 1 ?
Yes
No
REFH = 1 ?
Yes
No
Output on REFA is free
running (locked to MCLK).
The frequency is
programmed in FREQ[2:0] *.
REFH = 1 ?
Yes
Output high level.
No
Output on REFA is free
running (locked to MCLK).
The frequency is 1.544 MHz
in T1 mode or 2.048 MHz in
E1 mode.
Note *: '000' and '011' are reserved for FREQ[2:0] when REFA is free running.
Figure-42 REFA Output in LLOS Condition (When RCLKn Is Selected)
Functional Description
64
January 11, 2007