Datasheet
HMC5883L
12 www.honeywell.com
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.CRA default is 0x10.
CRA7
CRA6
CRA5
CRA4
CRA3
CRA2
CRA1
CRA0
(0)
MA1(0)
MA0(0)
DO2 (1)
DO1 (0)
DO0 (0)
MS1 (0)
MS0 (0)
Table 3: Configuration Register A
Location
Name
Description
CRA7
CRA7
Bit CRA7 is reserved for future function. Set to 0 when
configuring CRA.
CRA6 to CRA5
MA1 to MA0
Select number of samples averaged (1 to 8) per
measurement output.
00 = 1(Default); 01 = 2; 10 = 4; 11 = 8
CRA4 to CRA2
DO2 to DO0
Data Output Rate Bits. These bits set the rate at which data
is written to all three data output registers.
CRA1 to CRA0
MS1 to MS0
Measurement Configuration Bits. These bits define the
measurement flow of the device, specifically whether or not
to incorporate an applied bias into the measurement.
Table 4: Configuration Register A Bit Designations
The Table below shows all selectable output rates in continuous measurement mode. All three channels shall be
measured within a given output rate. Other output rates with maximum rate of 160 Hz can be achieved by monitoring
DRDY interrupt pin in single measurement mode.
DO2
DO1
DO0
Typical Data Output Rate (Hz)
0
0
0
0.75
0
0
1
1.5
0
1
0
3
0
1
1
7.5
1
0
0
15 (Default)
1
0
1
30
1
1
0
75
1
1
1
Reserved
Table 5: Data Output Rates
MS1
MS0
Measurement Mode
0
0
Normal measurement configuration (Default). In normal measurement
configuration the device follows normal measurement flow. The positive and
negative pins of the resistive load are left floating and high impedance.
0
1
Positive bias configuration for X, Y, and Z axes. In this configuration, a positive
current is forced across the resistive load for all three axes.
1
0
Negative bias configuration for X, Y and Z axes. In this configuration, a negative
current is forced across the resistive load for all three axes..
1
1
This configuration is reserved.
Table 6: Measurement Modes