ADIS16203CCCZ(Rev0) 데이터 시트보기 (PDF) - Analog Devices
부품명
상세내역
제조사
ADIS16203CCCZ Datasheet PDF : 28 Pages
| |||
ADIS16203
The ALM_MAG1 control register used in controlling the Alarm 1
function has two roles. The first role is to store the value with which
the output data variable is compared against to discern if an alarm
condition exists. The second role is to identify whether the alarm
should be active for excursions above or below the alarm limit. If 1 is
written to Bit 15 of the ALM_MAG1 control register, the alarm is
active for excursions extending above a given limit. If 0 is written to
Bit 15, the alarm is active for excursions dropping below the given
limit. The comparison value contained within the ALM_MAG1
control register is located within the lower 14 bits.
The monitored output register establishes the format of the
14-bit data space in the ALM_MAG1 and ALM_MAG2 registers. For
example, setting the alarm to monitor INCL_OUT sets the data
format to a 14-bit, twos complement number, which carries a bit
weight of 0.025°.
Use caution when monitoring the temperature output register for the
alarm conditions. Here, the negative temperature scale factor results
in the greater than and less than selections requiring reverse logic.
Setting Bit 11 in the ALM_CTRL register establishes the mode of
operation: threshold or rate of change (ROC). When the ROC
function is enabled, the comparison of the output data variable is
against the ALM_MAG1 level averaged over the number of samples
as identified in the ALM_SMPL1 control register. This acts to create
a comparison of (Δ units/Δ time) or the derivative of the output data
variable against a predefined slope.
The versatility built into the alarm function allows the user to adapt
to several applications. For example, in the case of monitoring twos
complement variables, Bit 15 within the ALM_MAG1 control register
can allow for the detection of negative excursions below a fixed level.
In addition, the Alarm 1 and Alarm 2 functions can be set to monitor
the same variable that allows the user to discern if an output variable
remains within a predefined window.
Another potential ROC application is to monitor slowly changing
outputs in the inclination level. With the addition of the alarm hard-
ware functionality, the ADIS16203 can be left to run independently
of the main processor and interrupt the system only when an alarm
condition occurs. Conversely, the alarm condition can be monitored
through the routine polling of any one of the seven data output registers.
Bits 4 and 5 in the ALM_CTRL register establishes whether
ALM_MAG1 and ALM_MAG2 are compared with filtered or
unfiltered data.
ALM_MAG1 Register Definition
Address
Default1
Format2
0x21, 0x20
0x0000
N/A
Access
R/W
1 Default is valid only until the first register write cycle.
2 Format is established by source of monitored data
The ALM_MAG1 register contains the threshold level for
Alarm 1. The contents of this register are nonvolatile.
Table 11. ALM_MAG1 Bit Designations
Bit
Description
15
Greater than Active Alarm Bit.
1: Alarm is active for an output greater than
ALM_MAG1 register setting.
0: Alarm is active for an output less than
ALM_MAG1 register setting.
14
Not used.
13:0 Data Bits. This number can be either twos complement
or straight binary. The format is set by the value being
monitored by this function.
ALM_SMPL1 Register Definition
Address
Default1
Format
0x25, 0x24
0x0000
Binary
1 Default is valid only until the first register write cycle.
Access
R/W
The ALM_SMPL1 register contains the sample period information
for Alarm 1, when it is set for ROC alarm monitoring. The ROC
alarm function averages the change in the output variable over the
specified number of samples and compares this change directly
to the values specified in the ALM_MAG1 register. The contents
of this register are nonvolatile.
Table 12. ALM_SMPL1 Bit Designations
Bit
Description
15:8 Not used
7:0
Data bits
Rev. 0 | Page 16 of 28
Share Link: 