AN4547
Application note
Migrating from STM32F407xx/417xx to
STM32F427xx/429xx/437xx/439xx
Introduction
Designers of STM32 microcontroller applications must have the possibility to easily replace
one microcontroller with another from the same product series. Reasons for migrating an
application to a different microcontroller can be for example;
to fulfill higher product requirements, extra demands on memory size, or an increased
number of I/Os.
to meet cost reduction constraints that require to switch to smaller components and shrink
the PCB area.
This application note is written as a help with the analysis of the steps involved when
migrating from an existing STM32F407xx/417xx-based design to the
STM32F427xx/429xx/437xx/439xx one withing the high performance STM32F4 series.
This application note gathers the most important information and presents the main
considerations to address.
Table 1
provides the list of products to which this document applies.
This application note is not exhaustive and comes as a complement of other product
specifications available on
www.st.com/stm32:
Datasheets
– DS8597 and DS8626 for STM32F407xx/417xx microcontrollers respectively,
– DS9405 and DS9484 for STM32F427xx/429xx/437xx/439xx microcontrollers
respectively.
Errata sheets
– STM32F405xx/407xx and STM32F415xx/417xx device limitations,
– STM32F427xx/437xx and STM32F429xx/439xx line limitations.
Reference manual
– RM0090 - STM32F405xx/07xx, STM32F415xx/17xx, STM32F42xxx and
STM32F43xxx advanced ARM®-based 32-bit MCUs
Programming manual
– PM0214 - STM32F3 and STM32F4 Series Cortex
®
-M4 programming manual
Application note
– AN4488 - Getting started with STM32F4xxxx MCU hardware development,
– AN2606 - STM32 microcontroller system memory boot mode.
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AN4547
Table 1. Applicable products
Reference product
STM32F407xx
STM32F417xx
STM32F427xx
Part numbers
STM32F407IE, STM32F407IG, STM32F407VE, STM32F407VG,
STM32F407ZE, STM32F407ZG
STM32F417IE, STM32F417IG, STM32F417VE, STM32F417VG,
STM32F417ZE, STM32F417ZG, STM32F427AG, STM32F427AI
STM32F427IG, STM32F427II, STM32F427VG, STM32F427VI,
STM32F427ZG, STM32F427ZI
STM32F429AG, STM32F429AI, STM32F429BE, STM32F429BG,
STM32F429BI, STM32F429GDIE, STM32F429IDIE, STM32F429IE,
STM32F429IG, STM32F429II, STM32F429JG, STM32F429JI,
STM32F429NE, STM32F429NG, STM32F429NI, STM32F429VE,
STM32F429VG, STM32F429VI, STM32F429ZE, STM32F429ZG,
STM32F429ZI
STM32F437AI, STM32F437IG, STM32F437II, STM32F437VG,
STM32F437VI, STM32F437ZG, STM32F437ZI
STM32F439AI, STM32F439BG, STM32F439BI, STM32F439GDIE,
STM32F439IDIE, STM32F439IG, STM32F439II, STM32F439JG,
STM32F439JI, STM32F439NG, STM32F439NI, STM32F439VG,
STM32F439VI, STM32F439ZG, STM32F439ZI
STM32F429xx
STM32F437xx
STM32F439xx
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Product feature comparison
1
Product feature comparison
Table 2
summarizes the main differences between the STM32F407xx/417xx and
STM32F427xx/429xx/437xx/439xx product features, and the impact on the hardware and
on the firmware of the application design when migrating from STM32F407xx/417xx to
STM32F427xx/429xx/437xx/439xx microcontrollers.
Table 2. Main product feature differences for safe migration
Feature
Power supply
STM32F407xx/417xx
1.8 V to 3.6 V on the whole
temperature range, reduced to
1.7 V in the 0°C to 70°C range
168 MHz
STM32F427xx/429xx/437xx/439xx
1.7 V to 3.6 V on the whole
temperature range
180 MHz with overdrive mode
enabled
Scale1
Scale 2
Scale 3
Can be modified only when PLL is
off
Up to 2 Mbyte, split on two banks
with two controllers. Supports dual
bank (RWW)
256 Kbyte of SRAM including
64 Kbyte of CCM,
4 Kbyte of backup RAM,
20 x 32-bit backup registers
FMC: extended with SDRAM
controller and supporting 32-bit
mode
Extended with GCM and SHA2
support
Three I2C enhanced with digital
filters to be programmed and
enabled/disabled by firmware
Maximum frequency
Voltage Scaling Output
(VOS)
Scale1
Scale 2
Can be changed on the fly
Flash size
Up to 1 Mbyte
128 Kbyte of SRAM including
64 Kbyte of CCM,
4 Kbyte of backup RAM,
20 x 32-bit backup registers
FSMC (16-bits)
RAM size and other
memories
Crypto/Hash
Enhanced peripherals
Three I2C
Up to three general purpose timers
All general purpose timers running
running at maximum system
at maximum system frequency
frequency
Other peripherals
Up to three SPI (with two I2S in full
duplex)
Up to six U(S)ARTs
-
New peripherals
-
-
Bootloader version
Refer to application note AN2606
Up to six SPI (with two I2S in full
duplex)
Up to eight U(S)ARTs
One Serial Audio Interface (SAI)
with dedicated PLL
LCD-TFT controller
Chrom-ART accelerator
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Table 2. Main product feature differences for safe migration (continued)
Feature
Pin list and packages
STM32F407xx/417xx
STM32F427xx/429xx/437xx/439xx
Refer to STM32F407xx/417xx datasheets,
STM32F427xx/429xx/437xx/439xx datasheets and AN4488
Incorrect BOR option byte when
consecutively programming BOR
option byte
Configuration of PH10 and PI10 as
external interrupts is erroneous
DMA2 data corruption when
managing AHB and APB
peripherals in a concurrent way
Slow down of APB clock during a
DMA transfer
Resolved
Resolved
Resolved
Resolved
Resolved but with changed
behavior: the temperature sensor is
connected to ADC_IN18 input,
same as VBAT
Resolved with new behavior to
enhance the accuracy
Modified behavior or
fixed limitations
Battery charge monitoring lower
than 2.4 V
Internal noise impacting the ADC
accuracy
I2S2 in full-duplex mode may not
work properly when SCK and WS
Recommendation added in the
signals are mapped on PI1 and PI0 datasheet.
respectively
SDIO clock divider BYPASS mode
may not work properly
Resolved
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Revision history
2
Revision history
Table 3. Document revision history
Date
25-Jun-2014
Revision
1
Initial release.
Changes
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