
IDT82V3202
EBU WAN PLL
Functional Description
18
September 11, 2009
3
FUNCTIONAL DESCRIPTION
3.1
RESET
The reset operation resets all registers and state machines to their
default value or status.
After power on, the device must be reset for normal operation.
For a complete reset, the RST pin must be asserted low for at least
50 s. After the RST pin is pulled high, the device will still be in reset
state for 500 ms (typical). If the RST pin is held low continuously, the
device remains in reset state.
3.2
MASTER CLOCK
A nominal 12.8000 MHz clock, provided by a crystal oscillator, is
input on the OSCI pin. This clock is provided for the device as a master
clock. The master clock is used as a reference clock for all the internal
circuits. A better active edge of the master clock is selected by the
OSC_EDGE bit to improve jitter and wander performance.
In fact, an offset from the nominal frequency may input on the OSCI
pin.
This
offset
can
be
compensated
by
setting
the
NOMINAL_FREQ_VALUE[23:0] bits. The calibration range is within
±741 ppm.
The performance of the master clock should meet GR-1244-CORE,
GR-253-CORE, ITU-T G.812 and G.813 criteria.
Bit
Register
Address (Hex)
NOMINAL_FREQ_VALUE[23:0]
NOMINAL_FREQ[23:16]_CNFG, NOMINAL_FREQ[15:8]_CNFG, NOMINAL_FREQ[7:0]_CNFG
06, 05, 04
OSC_EDGE
DIFFERENTIAL_IN_OUT_OSCI_CNFG
0A