ACS8525 LC/P
ADVANCED COMMUNICATIONS
Address (hex): 32 (cont...)
Register Name cnfg_operating_mode
FINAL
DATASHEET
Description
(R/W) Register to force the state Default Value
of DPLL1 controlling state
machine.
0000 0000
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
DPLL1_operating_mode
Bit No.
Description
Bit Value Value Description
[2:0]
DPLL1_operating_mode
This field is used to control the state of the internal
finite state machine controlling DPLL1. A value of
zero is used to allow the finite state machine to
control itself. Any other value will force the state
machine to jump into that state. Care should be
taken when forcing the state machine. Whilst it is
forced, the internal monitoring functions cannot
affect the internal state machine, therefore, the
user is responsible for all monitoring and control
functions required to achieve the desired
functionality.
000
Automatic (internal state machine controlled).
001
Free Run.
010
Holdover.
011
Not used.
100
Locked.
101
Pre-locked2.
110
Pre-locked.
111
Phase Lost.
Address (hex): 33
Register Name force_select_reference_source
Description
(R/W) Register used to force the
selection of a particular SEC for
DPLL1.
Default Value
0000 1111
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
forced_select_SEC_input
Bit 0
Bit No.
Description
Bit Value Value Description
[7:4]
[3:0]
Not used.
forced_select_SEC_input
Value representing the SEC to be selected by
DPLL1. Value of 0 hex will leave the selection to the
automatic control mechanism within the device.
Using this mechanism will bypass all the monitoring
functions assuming the selected input to be valid. If
the device is not in state “Locked” then it will
progress to state locked in the usual manner. If the
input fails, the device will not change state to
Holdover, as it is not allowed to disqualify the
source. The effect of this register is simply to raise
the priority of the selected input to “1” (highest). To
ensure selection of the programmed input
reference under all circumstances, revertive mode
should be enabled (Reg. 34 bit 0 set to “1”).
-
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010-1111
-
Automatic state machine source selection
Not used.
Not used.
DPLL1 forced to select input SEC1 TTL.
DPLL1 forced to select input SEC2 TTL.
DPLL1 forced to select input SEC1 DIFF.
DPLL1 forced to select input SEC2 DIFF.
Not used.
Not used.
DPLL1 forced to select input SEC3.
Not used.
Revision 3.01/August 2005 © Semtech Corp.
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