STMicroelectronics AN1474 Application Note for ST92F150 and ST92F120 Problem Resolution Guidelines

About this manual

This document outlines problem resolution guidelines for the ST92F120 and ST92F150 microcontroller family. It addresses issues related to external watchdog routine execution during bootcode and provides solutions for applications that fail to execute or communicate via ISP.

The note also details specific reset vector mapping behaviors, particularly for the 128Kbyte flash variant of the ST92F120. It explains how to handle parasitic resets during flash upgrades by ensuring the bootloader code is accessible and provides examples of startup files to redirect execution between sectors.

What's inside

• External Watchdog Routine
• ST92F120 Reset Vector
• Special Reset Vector Mapping
• Jump from Sector FO to F3
• Jump from Sector F3 to FO
• In Application Programming

Specifications

Frequently asked questions

What should be done if the application is not executed and ISP communication fails?

Modify the application code to fill address 0x000006h with Oxffffh if an external watchdog is not used, then erase and reprogram the device.

What address range is used for the external watchdog routine offset?

The routine address offset is located at addresses 0x000006h and 0x000007h.

What address must be filled with Oxffffh if an external watchdog is not used?

You must fill the word at the address 0x000006h with Oxffffh.

Where is the reset vector located in the ST92F120 128Kbyte Flash device?

In this device, the reset vector is located in 0x01E000h, at the begining of the sector F3.