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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LVDSE bits in SPMSC1 when the CPU executes a STOP instruction, then the voltage
regulator remains active during STOP mode. If the user attempts to enter the STOP1
with the LVD enabled in STOP (LVDSE = 1), the MCU enters STOP4 instead.
Table 20. STOP mode behavior
Mode STOP1 STOP4
LFO Oscillator, PWU Always On and Clocking
Free-Running Counter (FRC) Always On and Optionally Counting
Real-Time Interrupt (RTI)
[1]
Always On if using LFO as Clock
MFO Oscillator
[2]
Optionally On Optionally On
HFO Oscillator Off Off
CPU Off Standby
RAM Off Standby
Parameter Registers On On
FLASH Off Standby
TPM1 2-Chan Timer/PWM Off Off
Digital I/O Disabled Standby
Sensor Measurement Interface (SMI) Off Optionally On
Pressure P-cell Off Optionally On
Optional Acceleration g-cell Off Optionally On
Temperature Sensor (in ADC10) Off Optionally On
[3]
Voltage Reference (in ADC10) Off Optionally On
(3)
LFR Detector
[4]
Periodically On Periodically On
LFR Decoder Optionally On Optionally On
RF Controller, Data Buffer, Encoder Optionally On Optionally On
RF Transmitter
[5]
Optionally On Optionally On
ADC10 Off Optionally On
(3)
Regulator Off On
I/O Pins Hi-Z States Held
Wake-up Methods Interrupts, resets Interrupts, resets
Computer Operating Properly (COP) watchdog Off Off
[1] The interrupt from RTI operates from all power modes, however the RTIF flag will not be set and the interrupt service
routine will not execute if the RTI is configured and STOP1 mode entered. RTIF flag and the interrupt service routine
execute if in Run mode or if STOP4 is entered.
[2] MFO oscillator started if the LFR detectors are periodically sampled, the LFR detectors detect an input signal; a pressure
or acceleration reading is in progress or the RF state machine is sending data.
[3] Requires internal ADC10 clock to be enabled.
[4] Period of sampling set by MCU.
[5] RF data buffer may be set up to run while the CPU is in the STOP modes.
Specific to the tire pressure monitoring application the parameter registers and the LFO
with wake-up timer are powered up at all times whenever voltage is applied to the supply
pins. The LFR detector and MFO may be periodically powered up by the LFR decoder.
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