ADIS16250 Analog Devices, ADIS16250 Datasheet - Page 19

• Manufacturer Part Number: ADIS16250
• Description: Programmable Low Power Gyroscope
• Manufacturer: Analog Devices

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Alarms
The ADIS16250 provides two independent alarm options for
event detection. Event detections occur when output register
data meets the configured conditions. Configuration options are:
The ALM_MAG1 register and the ALM_MAG2 register both
establish the threshold level for detecting events. They take on the
format of the source data and provide a bit for establishing the
greater than/less than comparison direction. When making
dynamic comparisons, the ALM_SMPL1 register and the
ALM_SMPL2 register establish the number of averages taken for
the source data as a reference for comparison. In this configuration,
each subsequent source data sample is subtracted from the previous
one, establishing an instantaneous delta. The ALM_CTRL register
controls the source data selection, static/dynamic selection, filtering
selection, and digital I/O usage for the alarms.
The rate of change calculation is
Table 31. ALM_MAG1 Register Definition
Address
0x21, 0x20
Table 32. ALM_MAG1 Bit Designations
Bit
15
14
13:0
Table 33. ALM_SMPL1 Register Definition
Address
0x25, 0x24
Table 34. ALM_SMPL1 Bit Designations
Bit
15:8
7:0
Table 35. ALM_MAG2 Register Definition
Address
0x23, 0x22
•
•
•
•
•
Y
Y
M
Rate
Compare
N
y
C
C
(
DS
n
C
=
=
)
=
All output data registers are available for monitoring
as the source data
The source data can be filtered or unfiltered
Comparisons can be static or dynamic (rate of change)
The threshold levels and times are configurable
Comparison can be greater than or less than
=
=
factor to
of
N
Description
Comparison polarity: 1 = greater than, 0 = less than
Not used
Data bits: format matches source data format
Description
Not used
Data bits
magnitude
number
1
sampled
DS
change
Y
N
∑
n
C
=
DS
1
Default
0x0000
Default
0x0000
Default
0x0000
with
y
be
(
of
n
alarm
output
compared
+
for
samples
M
) 1
C
comparison
−
⇒
according
y
data
(
n
)
in
with
ALM_SMPL1/
Format
N/A
Format
Binary
Format
N/A
M
to
in
C
ALM_MAG1/2
ALM_MAG1/2
2
Access
R/W
Access
R/W
Access
R/W
MSB
(
>
or
Rev. 0 | Page 19 of 20
<
) ?
Table 36. ALM_MAG2 Bit Designations
Bit
15
14
13:0
Table 37. ALM_SMPL2 Register Definition
Address
0x27, 0x26
Table 38. ALM_SMPL2 Bit Designations
Bit
15:8
7:0
Table 39. ALM_CTRL Register Definition
Address
0x29, 0x28
Table 40. ALM_CTRL Bit Designations
Bit
15
14:12
11
10:8
7:5
4
3
2
1
0
Description
Comparison polarity: 1 = greater than, 0 = less than
Not used
Data bits: format matches source data format
Value
000
001
010
011
100
101
110
111
000
001
010
011
100
101
110
111
Description
Not used
Data bits
Default
0x0000
Default
0x0000
Rate of change (ROC) enable for alarm 2
Alarm 2 source selection
Rate of change (ROC) enable for alarm 1
Alarm 1 source selection
Not used
Filtered data comparison
Not used
Alarm output enable
Alarm output polarity
Alarm output line select
Description
1 = rate of change, 0 = static level
Disable
Power supply output
Gyroscope output
Inactive
Inactive
Auxiliary ADC output
Temperature sensor output
Inactive
1 = rate of change, 0 = static level
Disable
Power supply output
Gyroscope output
Inactive
Inactive
Auxiliary ADC output
Temperature sensor output
Inactive
1 = filtered data, 0 = unfiltered data
1 = enabled, 0 = disabled
1 = active high, 0 = active low
1 = DIO1, 0 = DIO0
Format
Binary
Format
N/A
ADIS16250
Access
R/W
Access
R/W