AN1575 Datasheet, PDF (1/11 Pages) STMicroelectronics – ON-BOARD PROGRAMMING METHODS FOR XFLASH AND HDFLASH ST7 MCUs

AN1575
APPLICATION NOTE
ON-BOARD PROGRAMMING METHODS
FOR XFLASH AND HDFLASH ST7 MCUs
by Microcontroller Division Applications
INTRODUCTION
This application note presents various ways of programming a Microcontroller (MCU) that has
already been soldered on a PCB. This “on-board” programming process can be used to up-
date either the whole firmware or only a set of data. The techniques described are fully sup-
ported features of the STMicroelectronics range of MCUs with embedded non-volatile memo-
ries (OTP, then FLASH) designed to meet the needs of equipment manufacturers and cus-
tomers. The ever-growing importance of Surface Mounted Devices (SMD) with high pin count
makes it more and more complex and costly to program with standard programming tools,
while the constraints of time-to-market and flexibility make it necessary to be able to program
or reprogram the products as late as possible in the production cycle, even at the final cus-
tomer site. Aside from these manufacturing considerations, the capability of an MCU to be re-
programmed in-situ opens new application fields: customization, performance upgrades, re-
mote maintenance, etc, are features that are valued by the end-customer.
Two main contexts have to be considered:
– Programming a MCU in the framework of a production line or when the application is not run-
ning (see Section 1).
– Programming the MCU ‘on the fly’ while it is running in the application, generally at the cus-
tomer site (see Section 2).
AN1575/1002
1/11
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