zl30410 Zarlink Semiconductor, zl30410 Datasheet - Page 14

• Manufacturer Part Number: zl30410
• Description: Multi-service Line Card Pll
• Manufacturer: Zarlink Semiconductor

Reset State
The Reset State must be entered when ZL30410 is powered-up. In this state, all arithmetic calculations are halted,
and clocks are stopped. The Reset state is entered by pulling the RESET pin low for a minimum of 1 µs. When the
RESET pin is pulled back high, internal logic starts a 625 µs initialization process before switching into the Free-run
state (MS2, MS1 = 10).
Free-Run State (Free-Run mode)
The Free-run state is entered when synchronization to a network reference is not possible or is not required.
Typically this occurs during installation or maintenance. In the Free-run state, the accuracy of the generated clocks
is determined by the accuracy and stability of the ZL30410 Master Crystal Oscillator.
Normal State (Normal Mode or Locked Mode)
The Normal State is entered when a good quality reference clock from the network is available for synchronization.
The ZL30410 automatically detects the frequency of the reference clock (8 kHz, 1.544 MHz, 2.048 MHz or
19.44 MHz) and sets the LOCK status pin high after acquiring synchronization. In the Normal state all generated
clocks (C1.5o, C2o, C4o, C6o, C8o, C16o, C19o, C34/C44 and C155) and frame pulses (F0o, F8o, F16o) are
synchronized to the master timing card. To guarantee uninterrupted synchronization, the ZL30410 has two
Acquisition PLLs that continuously monitor the quality of the incoming reference clocks. This dual architecture
enables quick replacement of a poor or failed reference and minimizes the time spent in other states.
Notes:
{AUTO} - Automatic internal transition
{MANUAL} - User initiated transition
--> - External transition
RESET=1
RESET
unconditional return from
any state to Free-run
MS2,MS1=10 forces
FREE-
RUN
10
MS2,MS1=00
MS2,MS1=01
OR
MS2,MS1=01 OR
RefSel change
Figure 5 - ZL30410 State Machine
OVER
HOLD-
01
Zarlink Semiconductor Inc.
ZL30410
MS2,MS1=00
Ref: OK AND
MS2,MS1
STATE
{AUTO}
14
RefSel Change
MS2,MS1=01
NORMAL
00
OR
Ref: OK-->FAIL AND
MS2,MS1=00
{AUTO}
HOLD-
OVER
AUTO
Ref: FAIL-->OK AND
MS2,MS1=00
{AUTO}
Data Sheet