Reset And Boot; Introduction; Boot Assist Flash; Test Flash Memory Block - STMicroelectronics SPC572L series Reference Manual

RM0400
7

Reset and Boot

7.1

Introduction

Resetting the SPC572Lx involves an entire process starting with the application of power to
fetching the first instruction of the user's application code.
The processor core on the SPC572Lx is based on the e200z215An3 architecture.
Memory elements involved in the boot-up process include:
•
UTEST flash memory.
•
TEST flash memory.
•
Boot Assist Flash (BAF).
7.1.1

Boot Assist Flash

The Boot Assist Flash (BAF) contains factory code to facilitate the device boot-up
procedure.
If the BAF code does not locate a valid boot header, it runs the Serial Boot Loader which
receives files from an external serial link controlled by the internal LINFlexD module. The
received file is placed in RAM and program execution begins at the start address specified
in the received file.
The Serial Boot Loader is only an option in the early stages of the device life cycle. In later
stages (for example FIELD) the device waits for the watchdog to reset the device if no boot
header is found.
7.1.2

TEST flash memory block

The TEST flash memory block contains Device Configuration Format (DCF) records used to
hold trim values and other variables, as well as general device configuration information.
The trim values are for:
•
Adjusting low-voltage and high-voltage detect circuit trip points.
•
Temperature sensor adjustments.
•
Power-on reset voltage trip point.
•
Analog-to-digital adjustments.
•
Internal RC oscillator (IRCOSC) trim values.
Note: The DCF records are written by the device manufacturer and programmed into TEST flash
memory during production testing. Further programming of the TEST flash is disabled at the
end of the factory test cycle.
7.1.3

UTEST flash memory block

The UTEST flash memory block also contains DCF records. Some UTEST DCF records are
written by the factory and programmed during production testing. Others are written by the
end user and programmed at the same time application code is programmed into the flash
memory. UTEST DCF records are used to set up various control and configuration registers,
including default memory configuration.
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