Freescale Semiconductor FRDM-FXS-MULTI 데이터 시트
MPL3115A2
Sensors
30
Freescale Semiconductor, Inc.
7.16
Maximum Temperature
7.16.1 T_MAX_MSB, T_MAX_LSB (0x24, 0x25)
Register with captured maximum temperature value.
The Temperature data is arranged as 12-bit 2’s complement value in degrees C. The 8 bits of T_MAX_MSB representing
degrees and with fractions of a degree stored in 4 bits in position 7-4 of T_MAX_LSB.
The register is cleared on power-up or manually by writing 0 to the registers
7.17
Control Registers
Note: Except for standby mode selection and OST (One Shot Mode), the device must be in STANDBY mode to change any
of the fields within CTRL_REG1 (0x26).
7.17.1 CTRL_REG1 (0x26)
Table 55. T_MAX_MSB Register
7
6
5
4
3
2
1
0
R
T_MAX 11
T_MAX 10
T_MAX 9
T_MAX 8
T_MAX 7
T_MAX 6
T_MAX 5
T_MAX 4
W
Reset
0
0
0
0
0
0
0
0
Table 56. T_MAX_LSB Register
7
6
5
4
3
2
1
0
R
T_MAX 3
T_MAX 2
T_MAX 1
T_MAX 0
0
0
0
0
W
Reset
0
0
0
0
0
0
0
0
Table 57. CTRL_REG1 Register
7
6
5
4
3
2
1
0
R
ALT
RAW
OS2
OS1
OS0
0
OST
SBYB
W
RST
Reset
0
0
0
0
0
0
0
0
Table 58. CTRL_REG1 Bit Descriptions
Name
Description
SBYB
This bit is sets the mode to ACTIVE, where the system will make measurements at periodic times based on the value of ST bits.
Default value: 0 (STANDBY)
0: Part is in STANDBY mode
1: Part is ACTIVE
Default value: 0 (STANDBY)
0: Part is in STANDBY mode
1: Part is ACTIVE
OST
OST bit will initiate a measurement immediately. If the SBYB bit is set to active, setting the OST bit will initiate an immediate
measurement, the part will then return to acquiring data as per the setting of the ST bits in CTRL_REG2. In this mode, the OST
bit does not clear itself and must be cleared and set again to initiate another immediate measurement.
One Shot: When SBYB is 0, the OST bit is an auto-clear bit. When OST is set, the device initiates a measurement by going into
active mode. Once a Pressure/Altitude and Temperature measurement is completed, it clears the OST bit and comes back to
STANDBY mode. User shall read the value of the OST bit before writing to this bit again.
measurement, the part will then return to acquiring data as per the setting of the ST bits in CTRL_REG2. In this mode, the OST
bit does not clear itself and must be cleared and set again to initiate another immediate measurement.
One Shot: When SBYB is 0, the OST bit is an auto-clear bit. When OST is set, the device initiates a measurement by going into
active mode. Once a Pressure/Altitude and Temperature measurement is completed, it clears the OST bit and comes back to
STANDBY mode. User shall read the value of the OST bit before writing to this bit again.
RST
Software Reset. This bit is used to activate the software reset. The Boot mechanism can be enabled in STANDBY and ACTIVE
mode.
When the Boot bit is enabled the boot mechanism resets all functional block registers and loads the respective internal registers
with default values.
If the system was already in STANDBY mode, the reboot process will immediately begin; else if the system was in ACTIVE
mode, the boot mechanism will automatically transition the system from ACTIVE mode to STANDBY mode, only then can the
reboot process begin.
mode.
When the Boot bit is enabled the boot mechanism resets all functional block registers and loads the respective internal registers
with default values.
If the system was already in STANDBY mode, the reboot process will immediately begin; else if the system was in ACTIVE
mode, the boot mechanism will automatically transition the system from ACTIVE mode to STANDBY mode, only then can the
reboot process begin.
The I
2
C communication system is reset to avoid accidental corrupted data access.
At the end of the boot process the RST bit is de-asserted to 0. Reading this bit will return a value of zero.
Default value: 0
0: Device reset disabled
1: Device reset enabled
Default value: 0
0: Device reset disabled
1: Device reset enabled