HMC5843 Datasheet, PDF (11/19 Pages) Honeywell Solid State Electronics Center – 3-Axis Digital Compass IC

HMC5843
Configuration Register A
The configuration register is used to configure the device for setting the data output rate and measurement configuration.
CRA0 through CRA7 indicate bit locations, with CRA denoting the bits that are in the configuration register. CRA7 denotes
the first bit of the data stream. The number in parenthesis indicates the default value of that bit.
CRA7
(0)
CRA6
(0)
CRA5
(0)
CRA4
DO2 (1)
CRA3
DO1 (0)
CRA2
DO0 (0)
CRA1
MS1 (0)
CRA0
MS0 (0)
Table 6: Configuration Register A
Location
CRA7 to CRA5
CRA4 to CRA2
CRA1 to CRA0
Name
0
DO2 to DO0
MS1 to MS0
Description
These bits must be cleared for correct operation.
Data Output Rate Bits. These bits set the rate at which
data is written to all three data output registers.
Measurement Configuration Bits. These bits define the
measurement flow of the device, specifically whether or
not to incorporate an applied bias to the sensor into the
measurement.
Table 7: Configuration Register A Bit Designations
The Table below shows minimum output data rates given PVT conditions. All three channels shall be measured within a
given data rate.
DO2 DO1
0
0
0
0
0
1
0
1
1
0
1
0
1
1
1
1
DO0 Minimum Data Output Rate (Hz)
0
0.5
1
1
0
2
1
5
0
10 (default)
1
20
0
50
1
Not used
Table 8: Data Output Rates
MS1 MS0 Mode
0
0
Normal measurement configuration (default). In normal measurement
configuration the device follows normal measurement flow. Pins BP and BN
are left floating and high impedance.
0
1
Positive bias configuration. In positive bias configuration, a positive current
is forced across the resistive load on pins BP and BN.
1
0
Negative bias configuration. In negative bias configuration, a negative
current is forced across the resistive load on pins BP and BN.
1
1
This configuration is not used.
Table 9: Measurement Modes
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