Atmel STK525 Installation manual

STK525
.............................................................................................
Hardware User Guide

STK525 Hardware User Guide User Guide 1
7608A–AVR–04/06
Section 1
Introduction...........................................................................................1-3
1.1 Overview...................................................................................................1-3
1.2 STK525 Starter Kit Features.....................................................................1-4
Section 2
Using the STK525.................................................................................2-6
2.1 Overview...................................................................................................2-6
2.2 Power Supply............................................................................................2-7
2.3 RESET....................................................................................................2-10
2.4 AT90USBxxx AVR Microcontroller..........................................................2-11
2.5 Serial Links .............................................................................................2-11
2.6 On-board Resources...............................................................................2-14
2.7 STK500 Resources.................................................................................2-19
2.8 In-System Programming .........................................................................2-20
2.10 Test Points..............................................................................................2-23
2.11 Configuration Pads .................................................................................2-24
2.12 Solder Pads ............................................................................................2-25
Section 3
Troubleshooting Guide .......................................................................3-26
Section 4
Technical Specifications .....................................................................4-27
Section 5
Technical Support...............................................................................5-28
Section 6
Complete Schematics.........................................................................6-29

STK525 Hardware User Guide 1-3
7608A–AVR–04/06
Section 1
Introduction
Congratulation for acquiring the AVR® STK525 Starter Kit. This kit is designed to give
designers a quick start to develop code on the AT90USBxxx and for prototyping and
testing of new designs.
1.1 Overview
This document describes the STK525 dedicated to the AT90USBxxx AVR
microcontroller. This board is designed to allow an easy evaluation of the product using
demonstration software.
To complement the evaluation and enable additional development capability, the
STK525 can be plugged into the Atmel STK500 Starter Kit Board in order to use the
AT90USBxxx with advanced features such as variable VCC, variable VRef, variable
XTAL, etc. and supports all AVR development tools.
To increase its demonstrative capabilities, this stand alone board has numerous on-
board resources (USB, RS232, joystick, data-flash, microphone and temperature
sensor).
This user guide acts as a general getting started guide as well as a complete technical
reference for advanced users.

Introduction
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Figure 1-1 . STK525 Board
1.2 STK525 Starter Kit Features
The STK525 provides the following features:
 AT90USBxxx TQFP device (2.7V<Vcc<5.5V),
 AVR Studio® software interface (1),
 USB software interface for Device Firmware Upgrade (DFU bootloader) (2)
 STK500 compatible
 Power supply flagged by “VCC-ON” LED:
– regulated 3 or 5V,
– from an external power connector,
– from the USB interface (USB device bus powered application),
– from STK500 (2),
 ISP connector for on-chip ISP,
 JTAG connector:
– for on-chip ISP,
– for on-chip debugging using JTAG ICE,
 Serial interfaces:
– 1 USB full/low speed device/host interface
– RS-232C ports with RTS/CTS handshake lines,
 On-board resources:
– 4+1-ways joystick,
–4LEDs,
– temperature sensor,
– microphone,
– serial dataflash memory,

Introduction
STK525 Hardware User Guide 1-5
7608A–AVR–04/06
 On-board RESET button,
 On-board HWB button for force bootloader section execution at reset.
 System clock:
– external clock from STK500 expand connectors
– 8 MHz crystal,
 Numerous access points for test.
Notes: 1. The STK525 is supported by AVR Studio®, version 4.12SP2 or higher. For up-to-date
information on this and other AVR tool products, please consult our web site. The
newest version of AVR Studio®, AVR tools and this User Guide can be found in the
AVR section of the Atmel web site, http://www.atmel.com.
2. ATMEL Flip®, In System Programming Version 3 or Higher shall be used for Device
Firmware Upgrade. Please consult Atmel web site to retrieve the latest version of Flip
and the DFU bootloader Hex file if needed.

STK525 Hardware User Guide 2-6
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Section 2
Using the STK525
This chapter describes the board and all its features.
2.1 Overview
Figure 2-1 . STK525 Overview
USB MiniAB RS232 JTAG ISP External Power
Joystick Potentiometer ResetCrystal Microphone
STK500 Expand0 STK500 Expand1
Data Flash
LEDS
Vcc Src.
Setting
TQFP64 Socket
Pin1
C Sensor
Vbus Gen.
Setting
Bootloader
Activation

Using the STK525
STK525 Hardware User Guide 2-7
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2.2 Power Supply
The on-board power supply circuitry allows various power supply configurations.
2.2.1 Power Supply Sources
The power supply source can come from three different (3) and exclusive sources:
 USB connector,
 JACK PWR connector (J6, See Figure 2-2),
 STK500
USB powered: When used as a USB device bus powered application, the STK525 can be powered via
the USB VBUS power supply line.
JACK PWR connector: – Need of a male JACK outlet,
– Input supply from 9 up to 15V (1) DC,
– No specific polarization (2) is required.
Figure 2-2 . JACK PWR Connector (J6)
Figure 2-3 . Male JACK Outlet and Wires
STK500 Powered: (c.f. “STK500 Resources” on page 19).
Notes: 1. 15V is the maximum level limitation of an unidirectional transit diode.
2. There is a diode (bridge) voltage level between the negative output of the power
supply and the STK525 “GND”. This could introduce some gap of voltage during
measurement and instrumentation.
3. Caution: Do not mount more than one power supply source on STK525.
+
-

Using the STK525
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2.2.2 Power Supply Setting
Table 2-1 . Power Supply(1) Setting
Notes: 1. Caution: The STK500 has its own “ON/OFF” switch
Vcc Source
Jumper position VCC power supply value Comments View
VBUS 5 VBUS
(4,7V to 5.0V)
This is the default configuration.
This should be used for a typicalUSB
device “bus powered” application.
In this mode, the STK525 is powered
directly from the USB bus, and no
other external power supply is
required.
REG 5 5V
This configuration can be used for a
USB “self powered” device
application” or when operating has a
USB host.
To use this configuration an external
power supply must be connected to
J6 connector.
REG 3.3 3.3V
This configuration allows the STK525
to be used in a 3V range application.
This configuration can be used with
both device or host mode USB
applications.
To use this configuration an external
power supply must be connected to
J6 connector.
STK Depends on STK500 VTG
setting
This configuration allows the STK525
to be used with an STK500 board.
In this mode, the STK525 power
supply is generated and configured
according to the “VTG” parameter of
the STK500 (1).
VCC
Source
Reg 5
Reg 3.3
VBUS 5
STK
VCC
Source
Reg 5
Reg 3.3
VBUS 5
STK
VCC
Source
Reg 5
Reg 3.3
VBUS 5
STK
VCC
Source
Reg 5
Reg 3.3
VBUS 5
STK

Using the STK525
STK525 Hardware User Guide 2-9
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2.2.3 VBUS Generator Setting
When using the AT90USBxxx microcontroller in USB host mode. The STK525 should
provide a 5V power supply over the VBUS pin of its USB mini AB connector.
A couple of transistors on the STK525 allows the UVCON pin of the AT90USBxxx to
control the VBUS generation (See Figure 2-4). In this mode the STK525 is powered by
external power supply source (J6 or STK500 expand0/1 connectors). JP7 allows to
select the 5V source used by the VBUS generator.
Figure 2-4 . VBUS generator schematic
Table 2-2 . VBUS Generator Setting
M1
FDV304P/FAI
R33
100k
VTG
STK
Ext
Q2
BC847B -
C34
4.7uF
2
1
3
JP7
VBUS gen R32
10k
UVCON
VBUS
“Vbus Gen”
Jumper position STK525 power supply Comments View
“Ext” External power supply from J6
This is the default configuration.
The VBUS generator source is the
on-board 5V regulator.
“Stk” External power supply from
Expand0/1 (connected to a STK500)
The VBUS generator source is the
STK500.
Note:
The “Vtarget” setting of STK500
should be set to “5V”.
Vbus
Gen
Ext
Stk
Vbus
Gen
Ext
Stk

Using the STK525
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2.2.4 “POWER-ON“ LED
The POWER-ON LED is always lit when power is applied to STK525 regardless of
power supply source and the regulation.
Figure 2-5 . “VCC-ON” LED
2.3 RESET
Although the AT90USBxxx has its on-chip RESET circuitry (c.f. AT90USBxxx
Datasheet, section “System Control and Reset), the STK525 provides the AT90USBxxx
a RESET signal which can come from 3 different sources:
2.3.1 Power-on RESET
The on-board RC network acts as power-on RESET.
2.3.2 RESET Push Button
By pressing the RESET push button on the STK525, a warm RESET of the
AT90USBxxx is performed.
Figure 2-6 . RESET Push Button (RST) Implementation