Bosch Sensortec"| BST-BMP581-DS004-02 18 | 74
Modifications reserved | Data subject to change
without notice Document number: BST-BMP581-DS004-02
ODR is not necessarily a value that is selectable via the ODR register. The resulting ODRs for the recommended OSR
settings are shown in Table 8.
4.3.7 Mode transitions
To go in STANDBY status the user must write ODR_CONFIG.pwr_mode = 0b00. The maximum transition time to
STANDBY is t
standby
. The effective status of the device is always observable reading back the same register. After a
commanded switch to standby, the user either needs to wait for t
standby
or check the status register for a successful
switch, before he can command the device to go to another mode, and before writing to any of the registers named in
3.3.8.
From STANDBY, it can be switched to CONTINUOS, FORCED or NORMAL mode by writing
ODR_CONFIG.pwr_mode register. Directly after the transition to an active mode, the first measurement will be
performed. It is recommended to set the desired measurement configuration, before switching the mode.
4.3.8 Mode-depending register write restrictions
A number of registers and register fields can only be updated when the device is in STANDBY mode. These are for
example the registers for NVM operations (see 3.8), but also configuration registers for the FIFO and IIR configuration.
The register descriptions state if this limitation applies to a register field. Write operations to these registers in a mode
other than STANDBY are lost. It is generally recommended to write configurations before switching into the
measurement mode.
4.3.9 Post-power-up procedure
After power up of the BMP581, it is available after t_powerup. The host should not initiate any communication with the
BMP581 before. Depending on the interface configuration, a dummy read should be the first access to the device (see
4.1).
It is recommended that the host checks the following status registers after a power-up:
read out the CHIP_ID register and check that it is not all 0
read out the STATUS register and check that status_nvm_rdy==1, status_nvm_err == 0
read out the INT_STATUS.por register field and check that it is set to 1; that means INT_STATUS==0x10
4.3.10 Soft reset
BMP581 can be reset by writing 0xB6 to the CMD register. The BMP581 will come out of the reset after t
soft_res.
Softreset must not be triggered during a NVM user programming sequence.
4.4 Measurements
4.4.1 Pressure and temperature measurement enable
The BMP581 can either measure temperature only, or both temperature and pressure. Pressure-only measurement is
not supported, as temperature data is needed for the temperature compensation of the pressure data.
1
Pressure and temperature will be measured if any of these conditions is true:
OSR_CONFIG.press_en ==1, or
FIFO_SEL.fifo_frame_sel == 0b10, or
FIFO_SEL.fifo_frame_sel == 0b11
If none of these settings is made, the sensor will measure temperature only.
1
However, the sensor can be configured to output the pressure only data to the FIFO, see Chapter 3.6.1
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