NXP Semiconductors UM11227 - RFM Module in STOP Modes

NXP Semiconductors
UM11227
NTM88 family of tire pressure monitor sensors
UM11227 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2020. All rights reserved.
User manual Rev. 6 — 24 April 2020
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10.8.5.4.6 MFO
The medium frequency oscillator (MFO) remains powered up when the MCU enters the
STOP mode only when the SMI has been initiated to make a pressure or acceleration
measurement; or when the RF transmitter’s state machine is processing data.
10.8.5.4.7 HFO
The HFO is halted in all STOP modes.
10.8.5.4.8 PWU
The PWU remains active regardless of any mode of operation.
10.8.5.4.9 ADC10
The internal asynchronous ADC10 clock is always used as the conversion clock. The
ADC10 can continue operation during STOP4 mode. Conversions can be initiated while
the MCU is the STOP4 mode. All ADC10 module registers contain their reset values
following exit from STOP1 mode. See Section 10.17.
10.8.5.4.10 LFR
When the LFR is enabled and the MCU enters STOP mode, the detectors in the LFR
remain powered up depending on the states of the bits selecting the periodic sampling.
See Section 10.15 for more details.
10.8.5.4.11 Band gap reference
The band gap reference should be enabled whenever the sensor measurement interface
requires sensor or voltage measurements.
10.8.5.4.12 TPM1
When the MCU enters STOP mode, the clock to the TPM1 module stops and the module
halts operation. If the MCU is configured to go into STOP1 mode, the TPM1 module is
reset upon wake-up from STOP and must be re-initialized.
10.8.5.4.13 Voltage regulator
The voltage regulator enters a low-power standby state when the MCU enters any of the
STOP modes except STOP4 (LVDSE = 1 or ENBDM = 1).
10.8.5.4.14 Temperature sensor
The temperature sensor is powered up on command from the MCU.
10.8.5.5 RFM module in STOP modes
The RFM’s external crystal oscillator (XCO), bit rate generator, PLL, VCO, RF data
buffer, data encoder, and RF output stage will remain powered up in STOP modes during
a transmission, or if the SEND bit has been set and DIRECT mode has been enabled.