ARTERY AT-START-F425 User manual

AT-START-F425 User Manual
2021.10.20 1Rev 1.00
www.arterytek.com
Getting started with AT32F425R8T7-7
Introduction
AT-START-F425 is designed to help you explore the high performance of the 32-bit microcontroller
AT32F425 that embeds ARM Cortex®-M4 core, and expedite application development.
AT-START-F425 is an evaluation board based on AT32F425R8T7-7 microcontroller. The device
contains such peripherals as LEDs, buttons, USB micro-B connector, type-A connector, ArduinoTM
Uno R3 extension interface. This evaluation board embeds AT-Link-EZ for debugging/programming
without the need of other development tools.

AT-START-F425 User Manual
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Contents
1Overview................................................................................................................. 5
1.1 Features ...................................................................................................................5
1.2 Definition of terms .................................................................................................... 5
2Quick start .............................................................................................................. 6
2.1 Get started................................................................................................................6
2.2 AT-START-F425 development toolchains ................................................................. 6
3Hardware and layout ............................................................................................. 7
3.1 Power supply selection............................................................................................. 9
3.2 IDD ........................................................................................................................... 9
3.3 Programming and debugging: embedded AT-Link-EZ .............................................. 9
3.4 Boot mode selection...............................................................................................10
3.5 External clock source .............................................................................................10
3.5.1 HEXT clock source.....................................................................................................10
3.5.2 LEXT clock source .....................................................................................................10
3.6 LEDs .......................................................................................................................11
3.7 Buttons ....................................................................................................................11
3.8 USB OTG ................................................................................................................11
3.9 0Ω resistors ............................................................................................................ 12
3.10 Extension interfaces ............................................................................................... 13
3.10.1 ArduinoTM Uno R3 interface.......................................................................................13
3.10.2 LQFP64 I/O extension interface.................................................................................14
4Schematic ............................................................................................................. 15
5Revision history................................................................................................... 19

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List of tables
Table 1. Boot mode selection jumper settings...................................................................................10
Table 2. 0Ωresistor settings ...............................................................................................................12
Table 3. ArduinoTM Uno R3 extension interface pin definition...........................................................13
Table 4. Document revision history....................................................................................................19

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List of figures
Figure 1. Hardware block diagram ......................................................................................................7
Figure 2. Top layer ...............................................................................................................................8
Figure 3. Bottom layer .........................................................................................................................8
Figure 4. Schematic (AT-Link-EZ).....................................................................................................15
Figure 5. Schematic (microcontroller)................................................................................................16
Figure 6. Schematic (power supply and peripherals)........................................................................17
Figure 7. Schematic (extension interfaces).......................................................................................18

AT-START-F425 User Manual
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1 Overview
1.1 Features
AT-START-F425 has the following characteristics:
AT-START-F425 has an on-board AT32F425R8T7-7microcontroller that embeds ARM Cortex®-
M4 32-bit core, 64 KB Flash memory and 20 KB SRAM, in LQFP64 7x7mm packages.
On-board AT-Link interface:
−On-board AT-Link-EZ can be used for programming and debugging (AT-Link-EZ is a
simplified version of AT-Link, without offline mode support)
−If AT-Link-EZ were disassembled from the board by bending it along the joint, this interface
can be connected to an independent AT-Link for programming and debugging.
Various power supply methods:
−USB bus of AT-Link-EZ
−USB OTG bus (VBUS) of AT-START-F425
−External 5 V power supply (E5V)
−External 3.3 V power supply
4 x LED indicators:
−LED1 (red) indicates 3.3 V power-on
−3 x USER LEDs, LED2 (red),LED3 (yellow) and LED4 (green), indicate operation status
User button and Reset button
8 MHz HEXT crystal
32.768 kHz LEXT crystal
On-board USB type-A and micro-B connectors in order to demonstrate OTG1 function
Rich extension interfaces are available for quick prototyping
−ArduinoTM Uno R3 extension interface
−LQFP64 I/O extension interface
1.2 Definition of terms
Jumper JPx ON
Jumper is installed.
Jumper JPx OFF
Jumped is not installed.
Resistor Rx ON
Short by solder or 0Ω resistor.
Resistor Rx OFF
Open.

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2 Quick start
2.1 Get started
Configure the AT-START-F425 board in the following sequence:
1. Check the Jumper’s position on board:
JP1 is connected to GND or OFF (BOOT0 = 0, and BOOT0 has an pull-down resistor in the
AT32F425R8T7-7);
JP2 is connected to USART1.
2. Connect AT_Link_EZ to PC via a USB cable (Type A to micro-B), and supply power to the
evaluation board via a USB connector CN6. LED1 (red) is always on, and three other LEDs
(LED2 to LED4) start to blink in turn.
3. After pressing the user button (B2), the blinking frequency of three LEDs are changed.
2.2 AT-START-F425 development toolchains
ARM®Keil®: MDK-ARM™
IAR™: EWARM

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3 Hardware and layout
AT-START-F425 board is designed around an AT32F425R8T7-7 microcontroller in LQFP64 7x7
mm package.
Figure 1 shows the connections between AT-Link-EZ, AT32F425R8T7-7 and their peripherals
(buttons, LEDs, USB OTG, and extension connectors)
Figure 2 and Figure 3 shows their respective locations on the AT-Link-EZ and AT-START-F425
board.
Figure 1. Hardware block diagram
AT32F425R8T7-7
I/O
I/O
I/O
I/O
NRST
Reset
button
User
button
Micro-USB
Arduino extension
interface
Arduino extension
interface
LQFP64 I/O extension interface
LQFP64 I/O extension interface
USB type-A
AT-Link
interface
AT-Link-EZ
User LED
LED2~LED4
Micro-USB

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Figure 2. Top layer
LQFP64 I/O extension interface
Arduino Uno extension interface
AT32F425R8T7-7
Arduino Uno
extension interface
USB Micro-B
connector
Jumper for USART1
and OTG1
Arduino Uno extension interface
LQFP64 I/O extension interface
HSE 8 MHz crystal
User
button
Reset
button
User LED
Jumper
for boot
mode
select
Power LED USART1
interface
AT-Link
interface
AT-Link-EZ
USB Type-A
connector
LEXT 32.768 kHz crystal
Jumper for IDD
measurement
Figure 3. Bottom layer

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3.1 Power supply selection
The AT-START-F425 can not only be provided with 5 V through a USB cable (either through USB
connector CN6 on AT-Link-EZ or USB OTG connector CN5 on AT-START-F425), but also be
provided with an external 5 V power supply (E5V). Then 5 V power provides 3.3 V for the
microcontroller and its peripherals using on-board 3.3 V voltage regulator (U2).
5 V pin of J4 or J7 can also be used as an input power, so the AT-START-F425 board can be
supplied through a 5 V power unit.
The 3.3 V pin of J4, or the VDD of J1 and J2 can be used as 3.3 V input directly, so AT-START-
F425 board can also be supplied by a 3.3 V power unit.
Note: 5 V power supply must be provided through USB connector (CN6) on AT-Link-EZ. Any other
method cannot power the AT-Link-EZ.
When another board is connected to J4, 5 V and 3.3 V can be used output power, J7’s 5V pin as 5
V output power, the VDD pin of J1 and J2 as 3.3 V output power.
3.2 IDD
When JP3 OFF (symbol IDD) and R4 OFF, an ammeter can be connected to measure the power
consumption of AT32F425R8T7-7.
JP3 OFF, R4 ON:
AT32F425R8T7-7 is powered. (Default setting and JP3 plug is not mounted before shipping)
JP3 ON, R4 OFF:
AT32F425R8T7-7 is powered.
JP3 OFF, R4 OFF:
An ammeter must be connected to measure the power consumption of AT32F425R8T7-7. If
there is no ammeter available, the AT32F425R8T7-7 cannot be powered.
3.3 Programming and debugging: embedded AT-Link-EZ
The evaluation board integrates Artery AT-Link-EZ for users to program/debug the
AT32F425R8T7-7 on the AT-START-F425 board. AT-Link-EZ supports SWD interface mode, SWO
debug, and a set of virtual COM ports (VCP) to connect to the USART1_TX/USART1_RX
(PA9/PA10) of AT32F425R8T7-7.
Please refer to AT-Link User Manual for complete details on AT-Link-EZ.
The AT-Link-EZ on board can be disassembled or separated from the AT-START-F425. In this
case, the AT-START-F425 can still be connected to the CN7 interface (not mounted before leaving
factory) of AT-Link-EZ through CN2 interface (not mounted before leaving factory), or to AT-Link, in
order to continue to program and debug the AT32F425R8T7-7.

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3.4 Boot mode selection
At startup, three different boot modes are available for selection through pin configuration.
Table 1. Boot mode selection jumper settings
Jumper
BOOT0 pin
configuration
Boot mode
JP1 to GND or be OFF
0
Boot from internal Flash memory (factory default setting)
JP1 to GND
1
Boot from boot loader code area or internal SRAM (1)
(1) Depending on the Nboot1 bit of the user system area.
3.5 External clock source
3.5.1 HEXT clock source
There are three methods to configure the external high-speed clock sources by hardware:
On-board crystal (Factory default setting)
On-board 8 MHz crystal is used as HSE clock source. The hardware must be configured: R26
and R27 ON, R28 and R29 OFF.
External oscillator from PH0
External oscillator is injected from the pin_75 of J2. The hardware must be configured: R28
ON, R26 and R27 OFF. To use PH1 as GPIO, R29 ON can be connected to the pin_6 of J2.
HSE unused
PH0 and PH1 are used as GPIOs. The hardware must be configured: R28 and R29 ON, R26
and R27 OFF.
3.5.2 LEXT clock source
There are three methods to configure the external low-speed clock sources by hardware:
On-board crystal (Factory default setting)
On-board 32.768 kHz crystal is used as LEXT clock source. The hardware must be configured:
R22 and R23 ON, R24 and R25 OFF
External oscillator from PC14
External oscillator is injected from the pin_3 of J2. The hardware must be configured: R24 and
R25 ON, R22 and R23 OFF.
LEXT unused
PC14 and PC15 are used as GPIOs. The hardware must be configured: R24 and R25 ON,
R22 and R23 OFF.