NXP Semiconductors
FXTH87E
FXTH87E, Family of Tire Pressure Monitor Sensors
16.3 Memory resource usage
The firmware uses the top 8192 bytes of the FLASH memory map. At address $FC00,
1024 bytes are protected from erasure, containing the sensitivity and offset coefficients
for the transducers and clocks.
The firmware uses no specific bytes of the RAM but will cause additional stacking of
temporary values.
The firmware uses two bytes ($008E and $008F) of the Parameter Registers for global
flags for all routines.
16.3.1 Software stack
The RESET firmware function sets the SP register to the last address in the RAM. The
user can change the default stack location to meet its own application needs.
17 Development support
17.1 Introduction
This chapter describes the single-wire BACKGROUND DEBUG mode (BDM), which uses
the on-chip BACKGROUND DEBUG controller (BDC) module.
17.1.1 Features
Features of the BDC module include:
• Single pin for mode selection and background communications
• BDC registers are not located in the memory map
• SYNC command to determine target communications rate
• Non-intrusive commands for memory access
• ACTIVE BACKGROUND mode commands for CPU register access
• GO and TRACE1 commands
• BACKGROUND command can wake CPU from STOP or WAIT modes
• One hardware address breakpoint built into BDC
• Oscillator runs in STOP mode, if BDC enabled
• COP watchdog disabled while in ACTIVE BACKGROUND mode
17.2 Background debug controller (BDC)
All MCUs in the HCS08 Family contain a single-wire BACKGROUND DEBUG interface
that supports in-circuit programming of on-chip nonvolatile memory and sophisticated
non-intrusive debug capabilities. Unlike debug interfaces on earlier 8-bit MCUs, this
system does not interfere with normal application resources. It does not use any user
memory or locations in the memory map and does not share any on-chip peripherals.
BDC commands are divided into two groups:
• ACTIVE BACKGROUND mode commands require that the target MCU is in ACTIVE
BACKGROUND mode (the user program is not running). ACTIVE BACKGROUND
mode commands allow the CPU registers to be read or written, and allow the user
FXTH87ERM
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2019. All rights reserved.
Reference manual
Rev. 5.0 — 4 February 2019
163 / 183
NXP [ NXP ]
