NXP Semiconductors FXTH870 D Series, Manual

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FXTH870xD
Sensors
Freescale Semiconductor, Inc.
133
14 Firmware
This section describes the software subroutines contained in the firmware section of the FLASH memory that the user can call
for various tasks and to reduce the software development time for the main internal operations.
14.1 Software Jump Table
All subroutines are accessed through a jump table located at the bottom of the firmware FLASH memory as described in Table 86 .
This allows upgrades in firmware without changing the software code of the user. All subroutines should be accessed with the
JSR instruction.
14.2 Function Documentation
The following subsections describe the details of the firmware routines. Further details can be found in the latest version of the
FXTH870xD Embedded Firmware User Guide.
14.2.1 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.
14.2.1.1 FXTH870x02 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
Freescale. Any future updates to these firmware routines will be contained in that file. A summary of the firmware routines
available is given in
Table 86 .
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 86. FXTH870x02 Single Z-axis Firmware Summary and Jump Table
Address Routine Description
E000 TPMS_RESET Master reset of complete device
E003 TPMS_READ_VOLTAGE 10-bit uncompensated bandgap voltage reading
E006 TPMS_COMP_VOLTAGE 8-bit compensation of 10-bit voltage reading
E009 TPMS_READ_TEMPERATURE 10-bit uncompensated temperature reading
E00C TPMS_COMP_TEMPERATURE 8-bit compensation of 10-bit temperature reading
E00F TPMS_READ_PRESSURE 10-bit uncompensated pressure reading
E012 TPMS_COMP_PRESSURE 9-bit compensation of 10-bit pressure reading
E015 TPMS_READ_ACCELERATION 10-bit uncompensated acceleration reading
E018 TPMS_COMP_ACCELERATION 9-bit compensation of 10-bit acceleration reading
E01B TPMS_READ_V0 10-bit uncompensated voltage reading on PTA0 pin
E01E TPMS_READ_V1 10-bit uncompensated voltage reading on PTA1 pin
E021 TPMS_LFOCAL LFO clock calibration
E024 TPMS_MFOCAL MFO clock calibration
E027 TPMS_WAVG Weighted average (2, 4, 8, 16 or 32)
E02A TPMS_RF_RESET Master reset of RFM
E02D TPMS_RF_READ_DATA Read RFM data buffer
E030 TPMS_RF_READ_DATA_REVERSE Read RFM data buffer in reverse bit order
E033 TPMS_RF_WRITE_DATA Write RFM data buffer
E036 TPMS_RF_WRITE_DATA_REVERSE Write RFM data buffer in reverse bit order
E039 TPMS_RF_CONFIG_DATA Configure RFM