ACS8520 View Datasheet(PDF) - Semtech Corporation
Part Name
Description
MFG CO.
'ACS8520' PDF : 150 Pages View PDF
ACS8520 SETS
ADVANCED COMMUNICATIONS
Address (hex): 0C
Register Name sts_current_DPLL_frequency
[7:0]
FINAL
DATASHEET
Description
(RO) Bits [7:0] of the current DPLL Default Value 0000 0000
frequency.
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bits [7:0] of sts_current_DPLL_frequency
Bit 1
Bit 0
Bit No.
Description
Bit Value Value Description
[7:0]
Bits [7:0] of sts_current_DPLL_frequency
*When Bit 4 (T4_T0_select) of Reg. 4B
(cnfg_registers_source_select) = 0 the frequency
for the T0 path is reported.
When this Bit 4 = 1 the frequency for the T4 path is
reported.
-
See register description of
sts_current_DPLL_frequency at address 0D hex.
Address (hex): 0D
Register Name sts_current_DPLL_frequency
[15:8]
Description
(RO) Bits [15:8] of the current
DPLL frequency.
Default Value 0000 0000
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
sts_current_DPLL_frequency[15:8]
Bit 2
Bit 1
Bit 0
Bit No.
Description
Bit Value Value Description
[7:0]
sts_current_DPLL_frequency[15:8]
This value in this register is combined with the value
in Reg. 0C and Reg. 07 to represent the current
frequency offset of the DPLL.
*When Bit 4 (T4_T0_select) of Reg. 4B
(cnfg_registers_source_select) = 0 the frequency
for the T0 path is reported.
When this Bit 4 = 1 the frequency for the T4 path is
reported.
-
In order to calculate the ppm offset of the DPLL with
respect to the crystal oscillator frequency, the value
in Reg. 07, Reg. 0D and Reg. 0C need to be
concatenated. This value is a 2’s complement
signed integer. The value multiplied by
0.0003068 dec will give the value in ppm offset
with respect to the XO frequency, allowing for any
crystal calibration that has been performed, via
cnfg_nominal_frequency, Reg. 3C and 3D. The
value is actually the DPLL integral path value so it
can be viewed as an average frequency, where the
rate of change is related to the DPLL bandwidth. If
Bit 3 of Reg. 3B is High then this value will freeze if
the DPLL has been pulled to its min or max
frequency.
Revision 3.02/October 2005 © Semtech Corp.
Page 67
www.semtech.com
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