
Freescale Semiconductor
Feature Phone Software Application Product Brief
Freescale Semiconductor, Inc., 2005. All rights reserved.
Figure 1-1. Software System Block Diagram
Feature Phone Application Software
Telephony Modules
- Type 1 & 2 Telephony Features
- Caller ID Parser
- Echo Canceller
- Full Duplex Speakerphone
Line Sample
Buffers
Audio Sample
Buffers
DAA Control
UART Buffer
Line Sample
Buffers
Keypad
(for TDC1)
Display
(for TDC1)
LCD Driver
Keypad Driver
SCI Driver
GPIO Driver
SSI and CODEC Drivers
Fully functional DSP-based telephone with speakerphone
and CLASS feature support
High quality, full duplex speakerphone with performance
optimization tools
Support for on-hook GR-30-CORE services:
—
Calling Number and Name Delivery
—
Dialable Directory Number
—
Visual Message Waiting Indicator
—
Call Qualifier
Support for off-hook GR-30-CORE services:
—
Calling Identity Delivery on Call Waiting
—
Calling Waiting Deluxe
Adaptive Line and Acoustic Echo Cancellation
Multi-line and VoIP conference bridge ready
Telcordia SR-3004 and SR-TSV-002476 compliant
Supported by Performance Expert
TM
(PE)
An adaptive line echo canceller with a preset tail length of
16ms that is adjustable in 8ms intervals up to 64ms
An acoustic echo canceller with a preset tail length of
24ms that is adjustable in 8ms intervals up to 64ms
EIA-470 DTMF dialer
Extension-in-use detection control
Tonal Ringing Generator
Command/Control interface via AT commands or direct
function calls
The feature phone application is a fully functional telephone based on the DSP5685x family that provides a highly flexible
framework for screenphone and telco service products. This flexibility permits device manufacturers to quickly add a custom
user interface and value-added convenience features, such as number and call log directories, voice announce for caller ID,
and digital answering/paging functions. The feature phone application can be expanded to support multi-line applications with
multi-line conferencing. Feature phone compatibility with telephone networks is worldwide for call origination, call termination
and speakerphone operation. Feature phone CLASS features are compatible with GR-30-CORE compliant networks (North
America). Figure 1 illustrates the system diagram of the feature phone.
The feature phone application’s customizable framework uses four telephony DSP modules. The application software contains
the main control loop and a real-time kernel that manages the telephone state and makes calls to dedicated PE modules to
perform various functions. The application software performs all start-up initialization and buffer allocation for the telephony
modules and hardware drivers and implements communications between device and peripheral drivers and the telephony
modules.
The feature phone application communicates with the telephony modules through a well-defined API. All input commands and
data samples are passed to the modules through one of three data structures contained within the function calls. These data
structures are used by the modules to perform their function and pass telephony events such as Caller ID information back to
the application software. A simple serial control interface using AT commands is provided to simplify integration into existing
products that contain a host controller.