NXP Semiconductors
FXTH87E
FXTH87E, Family of Tire Pressure Monitor Sensors
16.2.1 General rules
1. No output parameter can use the extreme codes (all zero’s or all one’s).
2. The all zero’s output code will always indicate a fault and the status byte will indicate
the source of the error.
3. While firmware is processing, CPU resources are unavailable for application.
4. Each measured parameter will return a limit code ($00, $FF or $1FF) if an error
occurs in its acquisition, except for the external ADC voltage measurements on the
PTA[1:0] pins.
5. External ADC voltage measurements on the PTA[1:0] pins will return a full range code
that is ratiometric to the supply voltage.
16.2.1.1 FXTH87E single Z-axis firmware routines
The details on the use and execution of each firmware routine is documented in the
CodeWarrior project file that is supplied by NXP. Any future updates to these firmware
routines will be contained in that file. A summary of the firmware routines available is
given in Table 161.
The firmware table is comprised of 3-byte entries where the first byte is the operational
code for the JMP instruction, and the following two bytes are the absolute address
pointing to the location of the firmware function.
Table 161.ꢀFXTH87Ex02 single Z-axis firmware summary and jump routines
Address
E000
E003
E006
E009
E00C
E00F
E012
E015
E018
E01B
E01E
E021
E024
E027
E02A
E02D
E030
E033
E036
E039
Routine
Description
Master reset of complete device
TPMS_RESET
TPMS_READ_VOLTAGE
TPMS_COMP_VOLTAGE
TPMS_READ_TEMPERATURE
TPMS_COMP_TEMPERATURE
TPMS_READ_PRESSURE
TPMS_COMP_PRESSURE
TPMS_READ_ACCELERATION
TPMS_COMP_ACCELERATION
TPMS_READ_V0
10-bit uncompensated band gap voltage reading
8-bit compensation of 10-bit voltage reading
10-bit uncompensated temperature reading
8-bit compensation of 10-bit temperature reading
10-bit uncompensated pressure reading
9-bit compensation of 10-bit pressure reading
10-bit uncompensated acceleration reading
9-bit compensation of 10-bit acceleration reading
10-bit uncompensated voltage reading on PTA0 pin
10-bit uncompensated voltage reading on PTA1 pin
LFO clock calibration
TPMS_READ_V1
TPMS_LFOCAL
TPMS_MFOCAL
MFO clock calibration
TPMS_WAVG
Weighted average (2, 4, 8, 16 or 32)
Master reset of RFM
TPMS_RF_RESET
TPMS_RF_READ_DATA
TPMS_RF_READ_DATA_REVERSE
TPMS_RF_WRITE_DATA
TPMS_RF_WRITE_DATA_REVERSE
TPMS_RF_CONFIG_DATA
Read RFM data buffer
Read RFM data buffer in reverse bit order
Write RFM data buffer
Write RFM data buffer in reverse bit order
Configure RFM
FXTH87ERM
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© NXP B.V. 2019. All rights reserved.
Reference manual
Rev. 5.0 — 4 February 2019
157 / 183
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