I2S Audio I/O Card
I2S AUDIO I/O CARD USER’S GUIDE
1. Introduction
The Unified Development Platform (UDP) provides a development and demonstration platform for Silicon
Laboratories microcontrollers, short-range wireless devices, and software tools, including the Silicon Laboratories
Integrated Development Environment (IDE).
Figure 1. Unified Development Platform Block Diagram
Rev. 0.1 7/12 Copyright © 2012 by Silicon Laboratories UPIO-USB-AUDIO
I2S Audio I/O Card
2. Relevant Documents
This document provides a hardware ove rview for the Unified Development Platform (UDP) system USB Audio I/O
card. Additional information on the UDP system can be found in the documents listed in this section.
2.1. Motherboard User’s Guide
The UDP Motherboard User’s Guide contains information on the motherboard features and can be found at
www.silabs.com/udp.
2.2. Card User’s Guides
The UDP MCU, I/O, and radio test card User’s Guides can be found at www.silabs.com/udp.
2.3. Examples
The Precision32™ Software Development Kit (SDK) includes example firmware using this board. More details on
the use of the board can be found in the examp le documentation. The SDK can be do wnloaded from the websit e
as part of the Precision32 package at www.silabs.com/32bit-software.
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I2S Audio I/O Card
USB Debug Adapter
Power
Adapter
(J20)
USB
Connector
(J16)
3. Hardware Setup
Refer to Figure 2 for a diagram of the hardware configuration
1. Connect an MCU card to the UDP motherboard slot.
2. Connect the I/O card to the UDP motherboard slot.
3. (Optional) Connect a radio test card to the radio test card slot in the UDP motherboard.
4. (Optional) Connect an EZLink card to the EZLink card slot in the UDP motherboard.
5. Connect the USB Debug Adapter to the 2x5 debug connector on the MCU card with the 10-pin ribbon
cable.
6. Connect one end of the USB cable to the USB connector on the USB Debug Adapter.
7. Connect the other end of the USB cable to a USB Port on the PC.
8. Connect the ac/dc power adapter to power jack J20 on the UDP motherboard. The board can also be
powered from the J16 USB or J1 mini USB connectors.
9. Move the S3 power switch on the UDP motherboard to the ON position.
Notes:
Use the Reset button in the IDE to reset the target when connected using a USB Debug Adapter.
Remove power from the target boa rd and the USB De bug Adapter before connecting or disconnecting the
ribbon cable from the target board. Connecting or disconnecting the cable when the devices have power
can damage the device and/or the USB Debug Adapter.
Th e MCU card can be used alone without th e motherboard . However, the motherboard must be powered if
an MCU card is connected.
Figure 2. Hardware Setup using the Unified Development Platform
Rev. 0.1 3
I2S Audio I/O Card
4. UPIO-USB-AUDIO I/O Card Overview
The USB Audio I/O card adds a microphone, codec, and headphone jack for audio development and an SD card
connector. The card connects to the I/O Card expansion slot on the UDP motherboard and provides complete
access to the MCU resources. Each expansion board has a unique ID that can be read out of an EEPROM or MCU
on the board, which enables software tools to recognize the connected hardware and automatically select the
appropriate firmware image.
Figure 3 shows the USB Audio I/O card.
Figure 4 and Figure 5 highlight some of the features of the USB Audio I/O card.
4 Rev. 0.1
Figure 3. UPIO-USB-AUDIO I/O Card
I2S Audio I/O Card
Push-Button
Switches
LEDs
Headphone
Jack
SD Card
Connector
Joystick Switch
Graphic
QVGA LCD
Potentiometer for
Volume Control
Microphone Input
Path
Codec
Figure 4. UPIO-USB-AUDIO I/O Card Features (Front)
Rev. 0.1 5
I2S Audio I/O Card
LCD and
Joystick MCU
EBID MCU
Figure 5. UPIO-USB-AUDIO I/O Card Features (Back)
4.1. Microphone Input
The microphone input system on the board consists of two input paths. When SW1 is in the upper position marked
with
codec, the microphone connects to the codec (U14). When SW1 is in the lower position, the microphone
connects to the ADC_IN1 UDP signal through a filter and gain circuit. This filter and gain circuit is biased with the
ADC_VREF UDP signal.
4.2. Codec (U14) and Headphone Jack (J9)
This codec accepts register writes over I2C using the I2C_SDA_EZR and I2C_SCL_EZR signals. The
TIMER_EX_A signal provides the clock, and I2SRX_DOUT_A and I2STX_DOUT_A are th e digi t al aud io dat a input
and output signals. The I2S word sync (WS) and clock (SCK) signals can source from either the I2S receiver or I2S
transmitter on the MCU card. The capacitors, resistors, microphone, and headphone jack connections surrounding
the codec are based on the manufacturer’s recommendations. Table 1 summarizes the codec connections.
Table 1. Codec Connections
Codec Signal UDP Signal
Command I2C data I2C_SDA_EZR
Command I2C clock I2C_SCL_EZR
External clock TIMER_EX_A
I2S word sync (WS) I2STX_DFS_A and I2SRX_DFS_A
I2S clock (SCK) I2STX_CLK_A and I2SRX_CLK_A
I2S input (to codec) data (SD) (DACDAT pin) I2SOUT_DOUT_A
I2S output (from codec) data (SD) (ADCDAT pin) I2SIN_DOUT_A
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I2S Audio I/O Card
4.3. Potentiometer (R68)
The potentiometer connects to the ADC_IN0 signal and can be used for volume control. The MCU card must
implement firmware to modulate the volume as the potentiometer value changes.
4.4. Switches and LEDs
The I/O card has two push-button switches (S2 and S4) and two LEDs (D1 and D2). The switches are normally
open and pull the signal voltage to ground when pressed. Table 2 shows the UDP signal connections for these
switches and LEDs.
Table 2. Switch and LED Connections
SW or LED UDP Signal
Push-Button Switch (S4) GPIO00
Push-Button Switch (S2) GPIO01
Blue LED (D2) PWR_3.3_BULK
Red LED (D1) GPIO02
4.5. Co-processor MCU (U7)
The I/O card has a C8051F380 co-processor MCU (U7) that controls the Graphic QVGA LCD (LCD1) and reads
the five-direction joystick switch (S1). This co-processor enables stand-alone demos that do not require a PC when
connected with an MCU card through the UDP motherboard.
4.5.1. Graphic QVGA LCD (LCD1)
The graphic QVGA LCD (LCD1) connects to the co-processor C8051F380 MCU EMIF through the J6 connector.
This color LCD (SDT022ATFT by Displaytech Ltd.) has a resolution of 320 x 240 resolution. The power
consumption of the LCD can be measured using the J8 header. Table 3 show the co-processor port pin
connections to the LCD.
Table 3. Joystick Switch Connections
LCD Signal
IM0 PWR_3.3_BULK
IM3
LEDA
VCC
DB10 P4.0
DB11 P4.1
DB12 P4.2
DB13 P4.3
DB14 P4.4
DB15 P4.5
DB16 P4.6
DB17 P4.7
RD P1.6
RS/SCL P3.0
WR P1.7
LCD_RESET P1.1
Co-processor Pin or
UDP Signal
Rev. 0.1 7
I2S Audio I/O Card
4.5.2. Joystick Switch
The I/O card has a five-position joystick switch (S1) that connects to the co-processor C8051F380 MCU. The
joystick is normally open and pulls a signal voltage to ground when the joystick is placed in one of the five
positions. Table 4 show the co-processor port pin connections to the joystick.
Table 4. Joystick Switch Connections
Joystick Position Co-processor Pin
Center P0.6
Up P0.2
Down P0.3
Left P0.4
Right P0.5
4.6. SD Card Connector (U10)
The SD card connector (U10) connects to any standard SD card. The card power from PWR_3.3_BULK can be
enabled or disabled by the SPI_PWR signal connected to GPIO03.
The connector includes two mechanical switches: one detects if a card is inserted, and one indicates the write
protection status of the card. The card detection switch connects to the GPIO04 signal. The JP3 header provides
access to both the switch signals.
4.7. EBID MCU (U1 1 )
The I/O card has a unique ID that can be read out from the Silicon Labs C8051F990 MCU (U11). This MCU
enables software tools to recognize the connected hardware and automatically select the appropriate firmware
image.
8 Rev. 0.1
I2S Audio I/O Card
UDP motherboard
power
to VIO
power
VIO IN power
to Radio card
power
Radio card IN
power
to VDD
power
VDD IN powerJ15 J14 J13
C8051F351
JP3 JP2 JP1R24
R15
R6
5. Using the I/O Card with the UDP Motherboard
5.1. Current Measurement
The power measurement circuitry on the UDP motherboard consists of a Silicon Labs C8051F351 8051 MCU that
measures both input voltage and current consumption of the MCU card, I/O expander, and radio test card. When
using the I/O card, install a shorting block on the UDP Motherboard J15 and J13 connecting the two left pins
together.
5.2. I/O Card Header Connections
The I/O card has four connectors with 100 pins each. These 400 pins are directly tied to the UDP mo therbo ard and
MCU cards. These signals are named and designed to support a wide variety of features and applications, and the
UPIO-USB-AUDIO card implements a subset of these connections.
The MCU cards and I/O cards are designed so that a maximum number of functions are shared between each
card. This allows a particular type of I/O card to be shared amongst all MCU cards that connect to the same
signals.
The I/O card slot includes the following components:
The UPIO-USB-AUDIO card implements the signals described in Table 6, Table 7, and Table 8, Table 9 in the
Appendix.
Figure 6. Power Measurement Diagram
H1 I/O card connector H1
H2 I/O card connector H2
H3 I/O card connector H3
H4 I/O card connector H4
Rev. 0.1 9
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