Analog Devices MICROCONVERTER ADUC814-28TSSOP User manual

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ADUC814 EVALUATION BOARD
REFERENCE GUIDE
MICROCONVERTER ADUC814
QUICKSTART DEVELOPMENT SYSTEM

aADuC814 Evaluation Board Reference Guide
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CONTENTS:
Evaluation Board Reference Guide
1) Evaluation Board Overview
2) Evaluation Board Features
3) Using the LDR demo circuit
4) External Junctions (Connectors)
5) Parts List
Figure 1: Reference Orientation of the ADuC814 Evaluation Board

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1.0 EVALUATION BOARD OVERVIEW
The ADuC814 –28TSSOP Evaluation board has the following features:
• 2 Layer PCB (5” X 4” Form Factor)
• 9V input power supply/9V battery connection, regulated to 5V on board
• 4 pin UART header to connect to the RS232 Interface Cable
• 5 pin ICE-UART header to connect to external emulator board.
• 64K bit (8k * 8 bit) SPI FRAM
• On board 32.768kHz Crystal
• Quad Op-amp
• Example LDR Sensor circuit on-board
• Reset/External Interrupt Buttons
• Power indicator/General Purpose LEDs
• Access to all ADC inputs from external header. DAC output channel buffered to external
header. All device Ports are brought out to external header pins
• Surface Mount and Through-Hole General Purpose Prototype Area
NOTES :
1. All references in this document to physical orientation, placement of connectors and components are made with respect to
a component side view of the board with the Battery Connector (J1) appearing in the top right hand corner of the board as
shown in figure 1.
2. The board is laid out to minimize coupling between the analog and digital sections of the board. To this end, the ground
plane is split with the analog section on the bottom right hand side and a digital plane on the rest of the board. The
regulated 5V power supply is routed directly to the digital section and is filtered before being routed into the analog section
of the board.

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2.0 EVALUATION BOARD FEATURES
Power Supply:
The user should connect the 9V battery via J1(-) and J1(+). The 9V supply is regulated via a linear
voltage regulator (U1). The 5V regulator output being used to drive the rest of the board directly.
Alternatively a 9V supply can be fed to the board via the 2.1mm input power socket (J2). The input
connector is configured as ‘CENTER NEGATIVE’ i.e. GND on the center pin and +9V on the outer
shield.
When on, the green LED (D5) indicates that a valid 5V supply is being driven from the regulator
circuit.
All active components are decoupled with 0.1uF at device supply pins to ground.
RS232 Interface:
The ADuC814 (U2) TXD and RXD lines are connected to the RS232 Interface Cable via connector
(J4). The Interface Cable generates the required level shifting to allow direct connection to a PC serial
port. This interface will be the main channel of interactive comms on the board. Ensure that the cable
supplied is connected to the board correctly i.e. DVDD is connected to DVDD and GND is connected
to GND.
Emulation Interface:
Single pin non-intrusive emulation is possible using the ADuC814 by connecting an emulator to the
DLOAD pin. J5 allows direct connection to the emulator board.
External Data Memory Interface:
The Evaluation board incorporates 8K x 8 SPI FRAM (U3). The 3 wire interface to this memory is SPI
Mode 0 and Mode 3 compatible. The FRAM is active by default but may be disabled by removing the
zero ohm resistor R8.
Analog I/O Connections:
Analog input signals can be applied to the ADuC814 via connector J7. ADC analog input channels 0
and 1 are buffered and filtered with a first order RC. The ADC4/DAC0 channel, has a buffer which is
set up for DAC mode. If using this analog I/O as an input the buffer should be removed from the
circuit. ADC3 and ADC5/DAC1 channels have direct connection from J7 to the ADuC814.
Crystal Circuit:
The board is fitted with a 32.768kHz crystal, from which the on-chip PLL circuit generates a 16.78
MHz clock.
On-Chip Band Gap Reference Buffer:
A buffered version of the on-chip voltage reference is provided on J7. This voltage is taken from the
CREF pin. The internal reference can be bypassed by connecting Vref and Cref inputs together via
solder bridge B1 and connecting the external reference to the Vref input. On the device, setting the
ADCCON1.6 bit allows the internal reference to be bypassed.

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Miscellaneous I/O:
RESET Input: The reset input is driven from the push button switch to allow the user manual access
to the reset button.
Note: The ADuC814 reset pin is schmitt triggered internally.
INT0INT0 Input : The INT0INT0 push button switch is located down the left side of the board beside the
Reset Input. It is driven directly to the INT0INT0 input on the ADuC814 (U2, Pin 5).
User LED: P3.3 on the ADuC814 drives the Display LED (D4). The CLR instruction turns the
LED on and the SETB instruction turns the LED off.
Switch S3 DLOAD
Function: Allows the user to select between Serial Download/Debug mode or Normal mode.
Use : Move S3 to DLOAD/DEBUG position to enter serial download mode or debug mode on
power-on or after a hardware reset (i.e. pressing reset button).
Move S3 to Normal position for normal device operation.

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3.0 USING THE LDR CIRCUIT
As can be seen from examining the schematic an example LDR circuit is connected shown in Figure 2
below:
Figure 2: Circuit diagram of the LDR Circuit
Using the sample code in C:\ADuC\code\adc\adcldr.asm the variation in the resistance of the ldr can be
seen by the reducing brightness of the output led as the amount of light is decreased.
ADCDAC
VDD
VDD
Application
Code
LK8
LK5

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4.0 EXTERNAL JUNCTIONS CONNECTORS
All Ports Pins, Timer I/O and Device Interface Signals are brought out to external connection points for
easy connection via the prototype area or external instruments as detailed below.
J7 Analog I/O Connector
The analog I/O connector J7 carries all ADC inputs and DAC output channels as well as the external
VREF and CREF inputs. The pinout and orientation of this connector is shown below.
Pin Function
1 ADC0
2 ADC1
3 ADC2
4 ADC3
5 ADC4/DAC0
6 ADC5/DAC1
7 CREF(Buffered)
8 VREF
9 AVDD
10 AGND
Table 1: Pin functions for Analog I/O connector J7
J5 (Port 3, Port 1.0 and Port 1.1)
This 10 way connector allows easy access to the general purpose port pins P3.0 –P3.7, P1.0 and P1.1 to
and from the ADuC814. The exact pinout of this port is shown in the file 814sch.pdf.
Pin Function
1 P3.0
2 P3.1
3 P3.2
4 P3.3
5 P3.4
6 P3.5
7 P3.6
8 P3.7
9 P1.0
10 P1.1
Table 1: Pin functions for Analog I/O connector J7

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J5 (SPI/I2C Connector)
J5 is situated to the right side of the board and gives access to both the SPI interfaces. The orientation
and pinout of the connector is given below.
Pin Function
1 SCLOCK
2 MOSI
3 MISO
4 SS
Table 2: Pin functions for SPI connector J7

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2.0 ADuC814 Evaluation Board Parts List
Qty. RefDes Value Part Description Supplier Cat No
1U1 ZR78L05G ZETEX 5V 200mA Regulator SOT-223 Farnell 572-329
1U2 ADUC814ARU
ADUC814BRU MicroConverter Analog Devices
1U3 FM25640-SRAMTRON SPI FRAM FutureElectronics Ltd
1U4 OP491GS Quad Single Supply Rail-to-Rail Op-amp Analog Devices
1C1 0.33uF 35V SMD Tantalum Cap, Taj-A Case Farnell 498-919
2C2 C310uF 10V SMD Tantalum Cap, Taj-A Case Farnell 197-130
9C4C7C8C9 C10 C11 C12 C13 C14 0.1uF SMD Ceramic Cap, 0603 Case Farnell 431-989
2C5C6(Not populated) 18pF SMD Ceramic Cap, 0603 Case Farnell
2D1 D2 D3 PRLL4002 Diode SMD Diode (SOD-87 case) Farnell 316-2734
1D4 Red LED SMD LED Farnell 515-607
1D5 Green LED SMD LED Farnell 515-620
1D6 Yellow LED SMD LED Farnell 515-619
1J1 Battery Connector Pair of 9V Snap on Battery Connectors Farnell 723-988
1J2 PCB Mounted Socket PCB Mounted Socket (2.1mm Pin Diameter) Farnell 224-959
1J3 2 Pin/5 Pin 90oSingle Row Header Farnell 143-104
1J4 4Pin 90oSingle Row HeaderFarnell 672-130
1J5, J7 10 Pin Single Row HeaderFarnell 511-766
1J6 4 Pin Single Row HeaderFarnell 511-729
5R1 R8R10 R12 R16 0Ω0.063W 1% SMD Resistor, 0603 case Farnell 772-227
3R2 R4 R11560Ω0.063W 1%SMD Resistor, 0603 case Farnell 911-203
1R3 1.5Ω0.063W 1%SMD Resistor, 0603 case Farnell 321-7772
3R5 R6 R91kΩ0.063W 1%SMD Resistor, 0603 case Farnell 911-239
1R7 4.7kΩ0.063W 1%SMD Resistor, 0603 case Farnell 911-318
2R13 R14 10Ω0.063W 1%SMD Resistor, 0603 case Farnell 910-995
1R15 20kΩ0.063W 1%SMD Resistor, 0603 case Farnell 357-1555
1R17 LDR MPY54C569 Light Dependant Resistor Farnell 179-611
1L1 Ferrite Bead 1206 Case Farnell 581-094

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2S1 S2 Push button Switch SMD sealed 6mm Push Button Switch Farnell 177-807
1S3Toggle Switch Single Pole 2 Position Slide SwitchFarnell 733-647
3T1 T2 T3 (Not populated) Testpoint Raised Loop Testpoint Farnell 240-345
1Y1 32.768 kHz XTAL Seiko MC-306 Farnell 300-3127
1PCB Bare Board Eval-ADuC814QS Rev. A Bare Board
4Each Corner PCB Stand-off Stick on mounting feet Farnell 148-922