NXP AN12524 Application note

AN12524

Migration from FXTH87/87E to NTM88

Rev. 3 — 22 March 2021 Application note

Document information

Information Content

Keywords FXTH87/87E, NTM88, Migration

Abstract This document presents the main differences between FXTH87/87E and

NTM88 from a software application point of view.

NXP Semiconductors

AN12524

Migration from FXTH87/87E to NTM88

Revision history

Revision Date Description

3 20210322 • Global: Performed minor grammatical, content, and typographic changes throughout.

• Inserted "Document information" table on the first page.

• Relocated the "Revision history" from the end of the document to the beginning to

conform to NXP document content guidelines.

• Section 2, replaced footnote in the first paragraph with a document reference and

added document references for AN12523 in the second paragraph directing user to the new Section 16 "References".

• Section 3, removed the note below Table 1.

• Section 4.1, revised as follows: – Revised "...FFh, security register configured to 82h, and reserved bytes2 in portions

of FLASH from FFDCh to FFDFh." to "FFh and security register configured to 82h." and removed footnote 2.

– Figure 1, revised the image.

• Section 6, Table 3, revised the first row deleting "FXTH87/87E" from the first column,

removed ", documented in the NTM88 firmware user guide" from the third column and added "TPMS_E_READ_ACCEL" to the second row first cell.

• Section 7, revised as follows: – Revised "...the user does not have to handle the stack allocation, it can be placed

at any address by the linker." to "...the user does not have to force the stack top address to 28Fh anymore."

– Table 4 revised "The user does not have to handle stack allocation." to "The user

does not have to force the stack top address to 28Fh."

• Section 8, replaced the footnote in the first paragraph with a document reference

directing user to the new Section 16 "References".

• Section 9.2, revised "part numbers" to "devices" in the third paragraph, and the the

last row of Table 6 and revised the footnote in Table 6.

• Section 10 "GPIOs", Section 11 "Conditions to raise LF receive error flag", and

Section 12 "RF pre-charge", three new sections added.

• Section 16, inserted new reference section.

2 20191210 • Section 2, revised the second paragraph removing the word "production".

• Section 4, revised the first and third paragraphs and Table 2.

• Section 4.1, revised as follows: – Revised all paragraphs. – Revised the image and caption for Figure 1. – Removed Figure 2, captioned "Memory map of the PTM88 and NTM88 using

library model."

• Section 5, revised the first and second paragraphs.

• Section 6, revised the last row of Table 3 and removed note before table.

• Section 7, added a note after the last bullet.

• Section 9.2, revised entire section including Table 6.

• Section 13, revised entire section.

1 20190722 Initial release

Application note Rev. 3 — 22 March 2021

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NXP Semiconductors

1 Introduction

This document presents the main differences between FXTH87/87E and NTM88 from a software application point of view.

Note: Unless otherwise stated, the term “NTM88” refers to both the engineering samples (PTM88) and the production samples (NTM88). In Section 4 "Memory map

and application model", a distinction is made between the engineering and production

samples. In all other sections, the information applies to both the engineering and production samples.

2 Getting started

AN12524

Migration from FXTH87/87E to NTM88

The IDE to develop NTM88 applications remains CodeWarrior. A patch installed to have access to the NTM88 target.

From a software application point of view, NTM88 supports only Library Model

Applications. NXP does not program NTM88 samples with embedded firmware functions.

Users familiar with Firmware Model Applications can refer to AN12523 provides information on the differences between these two models and how to migrate applications from a firmware model to a library model.

3 Pressure and acceleration transfer functions

FXTH87 and FXTH87E have different transfer functions for pressure and acceleration. For pressure and acceleration, FXTH87 and FXTH87E use a 10-bit representation for raw measurement of pressure and acceleration. However, for compensated measurement, a 9-bit representation is used.

NTM88 uses a 12-bit representation for raw measurement and a 10-bit representation for compensated measurement of pressure and acceleration.

Refer to the appropriate data sheet for actual compensated transfer functions because they differ from one part number to another.

Table 1. Bit representation of raw pressure and acceleration and compensated pressure and acceleration

Representation of raw

pressure and acceleration

FXTH87 and FXTH87E 10 bits 9 bits

NTM88 12 bits 10 bits

[1]

must be

[2]

. AN12523

Representation of compensated

pressure and acceleration

[2]

4 Memory map and application model

The memory map is the same between the FXTH87 and FXTH87E, but different for the NTM88.

During the production of FXTH87 and FXTH87E devices, NXP programs the firmware and trim between E000h and FFFFh. The user may choose to develop either firmwarebased applications or library-based applications. For firmware-based applications, the embedded firmware is used by the application. With library-based applications, the user erases the embedded firmware and reprograms the functions used by the application.

Application note Rev. 3 — 22 March 2021

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NXP Semiconductors

The PTM88xxxS alpha-engineering samples have been shipped with an embedded firmware. This is indicated for reference only as these samples are not distributed anymore. NXP programs PTM88xxx5 and NTM88 production samples with trim only. Without programmed firmware functions, only the library model is applicable for PTM88xx5 and NTM88.

Table 2. Engineering and production sample firmware and programming

FXTH87 and FXTH87E N/A

(alpha samples – not

provided anymore)

PTM88xxxS

PTM88xxx5

and NTM88

AN12524

Migration from FXTH87/87E to NTM88

Engineering samples Production samples

Firmware and trim programmed by

(already released to production)

Firmware and trim

programmed by NXP

between E800h and FFFFh.

No firmware function programmed. NXP programs only trim between FD40h and FDFFh. See Section 4.1. Only library model can be used.

NXP between E000h and FFFFh

Firmware and library

model can be used.

N/A

(alpha samples not

released to production)

4.1 Overview of the memory maps

FXTH87 and FXTH87E samples shipped by NXP are programmed with an embedded firmware containing:

• the firmware functions,

• a jump table allowing user application calls to the firmware functions,

• trim coefficients and

• firmware interrupt vectors.

For these products, customers may choose to

• use the firmware model by keeping the embedded firmware.

• use the library model by erasing the embedded firmware (trim page excluded) and

adding firmware functions used by the application from the firmware library.

Refer to AN12523

In contrast, NTM88 samples are programmed only with:

• Trim coefficients from FD40h to FDFFh that must not be erased. It is important to

preserve the whole page from FC00h to FDFFh and ensure that the application does not erase the page;

• Protection register configured to FFh and security register configured to 82h.

When the application reprograms the interrupt vectors, the whole page from FE00h to FFFFh is erased. The erasure implies the protection and security registers are set to FFh. A security register set to FFh secures the device and prevent any further BDM access. The user must ensure that the application code configures the security register to an unsecure status value, for example to value 82h.

[2]

for additional information.

The rest of the flash is left empty. For NTM88 samples, only the library model can be used since no firmware functions are programmed.

In NTM88, the section from FC00h to FD3Fh is indicated as “one-time programmable”. NXP does not program this section and the section may be programmed one time since it is empty. However, after "one-time programing," the user cannot erase the section. Flash may only be erased 512 bytes by 512 bytes. Erasing the FC00h to FD3Fh section would

Application note Rev. 3 — 22 March 2021

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NXP Semiconductors

aaa-0 34413

FXTH 87/87E using a

firmware-bas ed applic ation

Jump tabl e

Firmware ver sion

E0A0- E0A3

E000 -E092 /E08 F

E092 for F XTH87xx1x,

E08F for FXTH87x x02

DFE0- DFDF

C000 -DFDF

FD40 -FDFF FD40 -FDFF

FFB0- FFBF

FFE0- FFFF

E0A0- E0A3

C00 0-E0 9F

FC00 -FD3F

FFB0- FFBF

FFE0- FFFF

Protect ion and secu rity

Firmwar e functio ns

Firmwar e interrup t vectors

Appli cation inte rrupt vec tors

Trim section

Librar y version

Protecti on and secu rity

Firmware n ot erasabl e

Interru pt vector s

Trim section

Application cod e

Firmware functions from

the fir mware libr ary

Function s from the

applicat ion libra ries

Applic ation cod e

Functions f rom the

applica tion libr aries

FXTH 87/87E using a

librar y-based applica tion

FD40- FDFF

C00 0-FB FF

FC00- FD3F

FFB0- FFBF

FFE0- FFFF

Protecti on and secu rity

FFAC-FFAF Librar y version

One- time progr ammable

Interru pt vector s

Trim section

Applic ation cod e

Firmware function s from

the fir mware libr ary

Functions f rom the

applica tion libr aries

NTM88 using a

librar y-base d applica tion

Portions of FLASH progra mmed by NXP at p roducti on that are er ased and over wri tten by

librar y-based applica tions

Not progr ammed by NX P i.e. empty wh en customers recei ve the sampl es

erase the trim coefficients section which must not be done. Erasing the trim coefficients section results in non-functional sensors.

The NTM88 firmware function TPMS_FLASH_WRITE prevents write access between FD40h and FDFFh. TPMS_FLASH_WRITE may be used to write bytes between FC00h and FD3Fh with NTM88. In contrast, the FXTH firmware write access is forbidden in the whole trim page between FC00h and FDFFh. With both FXTH and NTM88, TPMS_FLASH_ERASE function cannot erase the trim page from FC00h to FDFFh.

Figure 1 shows the memory map of FXTH87/87E and NTM88.

AN12524

Migration from FXTH87/87E to NTM88

5 Firmware version and derivative descriptor bytes

Application note Rev. 3 — 22 March 2021

Figure 1. Memory map of the FXTH87/87E and NTM88 using firmware and library model

For FXTH87 and FXTH87E, the firmware version and the derivative descriptor bytes are documented as CODE0 and CODE1 in the data sheet. The firmware version CODE0 is programmed by NXP at production with the version of the embedded firmware. When using library model applications, the library version overwrites the firmware version.

For NTM88, they are documented in the data sheet as CODEF and CODEH and are placed at different addresses. The byte CODEF is not programmed by NXP at production. It contains the firmware library version after the user has programmed an application in the device.

NXP recommends customers always use the function TPMS_READ_ID to read these bytes. NXP does not recommend a direct read from memory because the location in FXTH87/87E is different from NTM88 and NXP may change the location.

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+ 10 hidden pages

NXP AN12524 Application note

Specifications and Main Features

Frequently Asked Questions

User Manual

1 Introduction

2 Getting started

3 Pressure and acceleration transfer functions

4 Memory map and application model

4.1 Overview of the memory maps

5 Firmware version and derivative descriptor bytes