82V3352EDG IDT [Integrated Device Technology], 82V3352EDG Datasheet - Page 26

• Manufacturer Part Number: 82V3352EDG
• Description: SYNCHRONOUS ETHERNET WAN PLL
• Manufacturer: IDT [Integrated Device Technology]

3.9
and Holdover, and three secondary, temporary operating modes: Pre-
Locked, Pre-Locked2 and Lost-Phase.
switch is under external control and the status of the selected input clock
takes no effect to the operating mode selection. The forced operating
mode switch is applicable for special cases, such as testing.
state machines for T0 automatically determine the operating mode
respectively.
3.9.1
T0_OPERATING_MODE[2:0] bits, as shown in
Functional Description
IDT82V3352
T0 DPLL supports three primary operating modes: Free-Run, Locked
When the operating mode is switched by force, the operating mode
When the operating mode is switched automatically, the internal
The
T0
SELECTED INPUT CLOCK STATUS VS. DPLL
OPERATING MODE
T0 SELECTED INPUT CLOCK VS. DPLL OPERATING
MODE
DPLL
operating
Figure 6. T0 Selected Input Clock vs. DPLL Automatic Operating Mode
15
mode
Pre-Locked2
mode
is
4
Table
10
controlled
15:
Pre-Locked
mode
9
by
12
1
the
3
5
8
Lost-Phase
26
Locked
mode
mode
Free-Run mode
Table 15: T0 DPLL Operating Mode Control
the internal state machine is shown in
automatically, the current operating mode is always indicated by the
T0_DPLL_OPERATING_MODE[2:0] bits. When the operating mode
switches, the T0_OPERATING_MODE
T0_OPERATING_MODE
2
When the operating mode is switched automatically, the operation of
Whether the operating mode is under external control or is switched
T0_OPERATING_MODE[2:0]
7
13
000
001
010
100
101
110
111
11
6
14
2
SYNCHRONOUS ETHERNET WAN PLL
bit is ‘1’, an interrupt will be generated.
Holdover
mode
Figure
T0 DPLL Operating Mode
1
Forced - Pre-Locked2
Forced - Pre-Locked
Forced - Lost-Phase
6.
Forced - Free-Run
Forced - Holdover
bit will be set. If the
Forced - Locked
Automatic
March 23, 2009