ACS8522A View Datasheet(PDF) - Semtech Corporation
Part Name
Description
MFG CO.
'ACS8522A' PDF : 118 Pages View PDF
ACS8522A SETS LITE
ADVANCED COMMS & SENSING
Address (hex): 40 (cont...)
FINAL
DATASHEET
Register Name cnfg_holdover_modes
Description
(R/W) Register to control the
Default Value 1000 1000
Holdover modes of the T0 DPLL.
Bit 7
Bit 6
Bit 5
auto_averaging fast_averaging read_average
Bit 4
Bit 3
mini_holdover_mode
Bit 2
Bit 1
Bit 0
holdover_frequency_value [18:16]
Bit No.
Description
Bit Value Value Description
5
[4:3]
[2:0]
read_average
Bit to control whether the value read from the
holdover_frequency_value register is the value
written to that register, or the averaged Holdover
frequency. This allows software to use the internal
averager as part of the Holdover algorithm, but use
manual Holdover mode plus software to enhance
the performance.
mini_holdover_mode
Mini-holdover is a term used to describe the state of
the DPLL when it is in locked mode, but it has
temporarily lost its input. This may be a temporary
state, or last for many seconds whilst an input is
checked for inactivity. The DPLL behaves exactly as
in Holdover, and the frequency can be determined
in the same selection of ways (instantaneously, fast
averaged or slow averaged).
holdover_frequency_value [18:16]
0
Value read from holdover_frequency_value is the
value written to it.
1
Value read from a holdover_frequency_value is
either the fast or slow averaged frequency as
determined by fast_averaging.
00
Mini-holdover frequency determined in the same
way as for full Holdover mode.
01
Mini-holdover frequency frozen instantaneously.
10
Mini-holdover frequency taken from fast averager.
11
Mini-holdover frequency taken from slow averager.
-
See Reg. 3F (cnfg_holdover_frequency) for details.
Revision 1.00/September 2007 © Semtech Corp.
Page 67
www.semtech.com
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