ACS8522A SETS LITE
ADVANCED COMMS & SENSING
Address (hex): 4B
FINAL
DATASHEET
Register Name cnfg_registers_source_select
Description
(R/W) Register to select the
Default Value 0000 0000
source of many of the registers.
Bit 7
Bit 6
Bit 5
Bit 4
T4_T0_select
Bit 3
Bit 2
Bit 1
Bit 0
frequency_measurement_channel_select
Bit No.
Description
Bit Value Value Description
[7:5]
4
[3:0]
Not used.
-
-
T4_T0_select
Bit to select between the T0 and T4 path for:
Reg. 0A, 0B (sts_priority_table)
Reg. 0C, 0D and 07 (sts_current_DPLL_frequency)
Reg. 77, 78 (sts_current_phase)
0
T0 path registers selected.
1
T4 path registers selected.
frequency_measurement_channel_select
Register to select which input channel the
frequency measurement result in Reg. 4C
(sts_freq_measurement) is taken from.
0011
Frequency measurement taken from input SEC1.
0111
Frequency measurement taken from input SEC2.
1000
Frequency measurement taken from input SEC3.
1001
Frequency measurement taken from input SEC4.
All other values Not used- refers to no input channel.
Address (hex): 4C
Register Name sts_freq_measurement
Description
(RO) Register from which the
frequency measurement result
can be read.
Default Value 0000 0000
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
freq_measurement_value
Bit 2
Bit 1
Bit 0
Bit No.
Description
Bit Value Value Description
[7:0]
freq_measurement_value
-
This is an 8-bit 2’s complement signed integer. To
This represents the value of the frequency
calculate the offset in ppm of the selected input
measurement on the channel number selected in
channel, this value should be multiplied by
Reg. 4B (cnfg_registers_source_select). This value
3.81 ppm.
will represent the offset in frequency from the clock
to the frequency monitors. This can be either the
crystal oscillator to the device, or the output of the
T0 DPLL as selected in Reg. 48 Bit 7 cnfg_monitors.
Revision 1.00/September 2007 © Semtech Corp.
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