Integration Guide
Table Of Contents
- 1 Introduction
- 2 Module Power
- 3 Interfaces
- 4 Hardware Design Guidelines
- Advanced Tips for an RF-Friendly Layout
- Audio Reference Design
- Control Connector Signal Descriptions and Functions
- Module Power (PINS 87, 89, 91, 93, 95, 97, 99)
- Modem Power-on and Recovery Techniques
- Power Switch Logic Detect (Pin 85)
- ON/OFF (PIN 37)
- Phone On - PON (PIN 35)
- Internal Power Switch
- Voltage Reference - VREG_MSME1.8 (PIN 77)
- USB (PINS 1, 3, 5, 7)
- General Purpose Input/Output Interface
- RTC Sleep
- Serial Interfaces and Handshake (Pins 11, 13, 15, 17, 19, 21, 23, 25)
- UART 2 (Pins 27, 29)
- Digital Audio Interface (Pins 12, 14, 16, 18)
- 32 kHz Output (PIN 56)
- Analog-to-Digital Inputs (PIN 44 and 74)
- Handset Microphone Input (PINS 65, 67)
- Handset Microphone BIAS Output (PINS 53, 63)
- Handset Speaker Output (PINS 71, 73)
- Headset Microphone Input (PIN 55)
- Headset Speaker Output Left and Right (PINS 57, 59)
- Headset Detect (PIN 47)
- Circuit Protection
- 5 USB Driver Installation
- 36 -
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Tying DTR (pin 17) and RTS (pin 11) to ground to “spoof” flow control will cause the
modem to draw more current.
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We do not recommend leaving DTR (pin 17) and RTS (pin 11) unconnected. If you are not
going to use these signals, do one of the following:
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Pull up DTR (pin 17) and RTS (pin 11) through a 100K resistor; or
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Tie RTS (pin 11) to CTS (pin 13), and tie DTR (pin 17) to DSR (pin 25) on the modem
to loopback the signals.
UART 2 (Pins 27, 29)
UART2 supports RX and TX only.
Signal Min Max
VIH - High-level input voltage 1.85V 3.15V
VIL - Low-level input voltage -0.3V 0.95V
VOH - High-level output voltage 2.35V 2.85V
VOL - Low-level output voltage 0V 0.45V
Digital Audio Interface (Pins 12, 14, 16, 18)
This port is only available in Master mode and to be used for PCM digital audio. Below are the
settings for
configuring its operation and the interface specification:
Digital Audio Configuration
The default settings for the digital audio are:
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Mode = Master
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MCSI_CLK = 2.048 MHz
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Word Size = 16 Bits
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Sync Pulse = 8 KHz
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Frame mode = burst
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Clock edge Sync = rising edge
The following command is required to set the unit up in digital audio mode:
AT$voicepth=2
This configures the module to use digital audio instead of analog audio.
Digital Audio Data Format
The 16 bit word is sent MSB first. Data received is also MSB first. No other data manipulation is
done