CCITT V.42 Error Correction (LAPM and MNP2-4)
CCITT V.42bis Data and MNP Class 5 Compression
FAX Modem
V.17/V.29/V.27ter/V.21 Channel 2
T.30 Protocol
V.120
V.110
PPP Asynchronous Framing Support (RFC 1662)
Low Power
80 mW per Channel Typical Active
Low Power and Sleep Modes
On-Chip DS0/DS1 Interface
Full Function DMA Port
No External Memory Required
3.3 V Supply
Fully Upgradable RAM-Based Architecture
Fast Download
Full Image in 5 ms
High Speed 16-Bit Port Link Bus Provides Simple
Interface Between Host and Modem Pool
Gateway Processor Solution
ADSP-21mod970-110
INTRODUCTION
The ADSP-21mod970-110 is a six-channel solution intended
for remote access server and remote access concentrator applications. It combines a highly integrated DSP processor with
downloadable software. All datapump and controller functions
are implemented on a single 1.45-square-inch chip. This modem
package allows the highest modem port density while achieving
the lowest power consumption in a software upgradable platform.
The ADSP-21mod970-110 is designed for high-density systems
such as remote access servers, see Figure 1. Its high performance
DSP core, large on-chip SRAM, TDM serial port and 16-bit
DMA port provide efficient control and data communication
with minimal chip count. The modem software provides a number of data modulations, such as V.34, 56 kbps PCM and ISDN
with a software upgrade path to future standards and new applications, such as voice over network. The host interface allows
system access to modem statistics such as call progress, connect
speed and modulation parameters such as retrain count and
symbol rate.
ON-CHIP SRAM
The ADSP-21mod970-110 processor integrates 960K bytes
of on-chip memory. The modem datapump and controller
software, as well as data storage, are contained in the on-chip
SRAM. The SRAM cells are designed by Analog Devices. These
cells are optimized for high speed digital signal processing and
low power consumption. You can dynamically configure the
ADSP-21mod970-110 with software through the 16-bit DMA
interface.
DMA INTERFACE
The 16-bit internal DMA port (DMA Port) provides transparent, direct access to the on-chip RAM of the ADSP-21mod970-110
processor. This high speed access to on-chip memory simplifies control and data communication and system debug. Use the
16-bit DMA interface to dynamically configure the ADSP21mod970-110 with software.
K56Flex is a trademark of Rockwell International and Lucent Technologies.
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Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
The ADSP-21mod970-110 processor incorporates two complete
synchronous, double-buffered serial ports for serial communications. The serial ports interface directly to a time-division
multiplexed (TDM) 1544 kbps (T1) or 2048 kbps (E1) serial
stream, to an 8K sample/s data stream, or to an 8-bit companded
(64 kb/s) data stream (DS0). The serial ports operate under
modem software control.
SUPPORTED SYSTEM ARCHITECTURES
The ADSP-21mod970-110 Multiport Internet Gateway Processor supports two system architectures: serial Telco PCM TDMdata stream and parallel Telco PCM data stream. The two architectures are differentiated by the method of proving Telco PCM
data to the DSP Modem.
Serial Telco PCM TDM Data Stream Architecture
The serial Telco PCM TDM data stream architecture, shown in
Figure 2, is the most common architecture. In this architecture,
the modem pool may have a local Telco interface that provides
a serial TDM data stream of Telco PCM data to the DSP through
the DSP’s Serial Port. You can connect up to 24/32 DSPs,
through the Serial Port, to a 24-/32-channel serial TDM data
stream.
The parallel Telco PCM data stream architecture, shown in
Figure 3, provides a single bus interface for all data and control.
In this architecture, the modem pool may have a remote Telco
interface that provides a parallel data stream of Telco PCM data
to the DSP through the DSP’s DMA Port. An arbitrary number
of DSPs can be connected, through the DMA Port, to a Host
that provides the parallel data stream.
Note: The number of parallel DSPs is limited only by the software loading constraints on the Host.
HOST
MEMORY
I/F
DMA
PORT
ADSP-21mod970
ADSP-21mod970
ADSP-21mod970
ADSP-21mod970
ADSP-21mod970
ADSP-21mod970
HOST
ADSP-21mod970
ADSP-21mod970
TELCO PCM
I/F
Figure 2. Serial Telco PCM TDM Data Stream Architecture
Figure 3. Parallel Telco PCM Data Stream Architecture
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TELCO PCM
I/F
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ADSP-21mod970-110
SOFTWARE INTERFACE
Analog Devices provides sample C code for the software interface to the ADSP-21mod970-110. The software interface encompasses the following four areas—download, control interface,
data interface and modem statistics.
Download
The DMA Port on the ADSP-21mod970-110 contains an autoincrementing address generator. The host writes the starting
address of the transfer and then writes the first word of data.
After the first write, the DMA address generator automatically
increments; the host writes the next data word and the DMA
transfers that word to the next location in ADSP-21mod970110 memory.
The executable image contains code and data that must be
loaded into program and data memory. Program memory on the
ADSP-21mod970-110 is 24 bits wide, therefore two transfers
are used to load each word of program memory.
The host begins the download by asserting the RESET pin of
the ADSP-21mod970-110. The host then transfers all code and
data. All internal memory can be loaded in 5 ms.
Control Interface
The ADSP-21mod970-110 is controlled through two FIFOs in
DSP memory. The host sends a control event by writing to the
host-to-modem FIFO. The ADSP-21mod970-110 posts events to
the host by writing into the modem-to-host FIFO.
Data Interface
All data transferred to and from the ADSP-21mod970-110
passes through word FIFOs located in internal memory on the
ADSP-21mod970-110. The FIFOs are accessed through a
control structure that contains a pointer to the start of the FIFO
in memory, the length of the FIFO in 16-bit words, a pointer to
the next address to be read, and a pointer to the next address to
be written. The transmit and receive FIFOs are 1024 bytes
deep. Example code providing primitives for accessing the byteFIFOs is available from Analog Devices. Table I shows an example of a data FIFO.
Table I. FIFO Example
BASE
PD_PTR
WR_PDR
BASE + SIZE
Modem Statistics
INFO
INFO
INFO
INFO
Several modem statistics can be gathered through the DMA
Port. These statistics include call status, modulation in use,
connect rate, transmit and receive data rate, symbol rate, retrain
count, rate renegotiation count and others. Table II and Table IV
contain a complete listing of available modem statistics.
Modem Configuration
The modem is configured by programming various parameters
through the DMA Port. Table III and Table V contain complete
lists of modem configuration parameters.
Table II. Shell Status
Reference #Function
SS. 0Product Number
SS. 1Application Version
SS. 2Application Type
SS. 3Programmable Flag Data
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Table III. Shell Parameters
Reference #Function
SP. 0Serial Port Tx Time Slot
SP. 1Serial Port Rx Time Slot
SP. 2Serial Port Configuration
SP. 3Programmable Flag Control
SP. 4Programmable Flag Data
SP. 5Host Interrupt Count
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ADSP-21mod970-110
Table IV. Modem Status
Reference # Function
MS. 0Data Modulation State
MS. 1SNR MSE Measure
MS. 2Rx Level dBm
MS. 3Tx Level dBm
MS. 4Tx V.34 Symbol Rate
MS. 5Rx V.34 Symbol Rate
MS. 6Round Trip Delay
MS. 7Telemetry Data Update
MS. 8Constellation X
MS. 9Constellation Y
MS. 10Variable 2 X Pointer
MS. 11Variable 2 Y Pointer
MS. 12Variable 3 X Pointer
MS. 13Variable 3 Y Pointer
MS. 14Variable 4 X Pointer
MS. 15Variable 4 Y Pointer
MS. 16Data Modulation Monitor Retrain Local Count
MS. 17Data Modulation Monitor Retrain Remote Count
MS. 18Data Modulation Monitor Retrain Auto Count
MS. 19Data Modulation Monitor Renegotiate Local
Count
MS. 20Data Modulation Monitor Renegotiate Remote
Count
MS. 21Data Modulation Monitor Renegotiate Auto
Count
MS. 22Omc Carrier Family
MS. 23Omc Disconnect Reason
MS. 24Omc State
MS. 25Omc Time
MS. 26Omc Idle Time Start
MS. 27Omc Data Protocol Time Start
MS. 28Omc Initial Rx Data Rate
MS. 29Omc Current Rx Data Rate
MS. 30Omc Initial Tx Data Rate
MS. 31Omc Current Tx Data Rate
MS. 32Data Protocol
MS. 33Data Protocol Compression
MS. 34Data Protocol Rx HDLC Error Frame Count
MS. 35Data Protocol Rx HDLC Frame Count
MS. 36Data Protocol Tx HDLC Frame Count
MS. 37Data Protocol Tx Data Frame Count
MS. 38Data Protocol Tx Data Frame Retransmit Count
MS. 39Data Protocol Rx Data Frame Count
MS. 40Data Protocol Rx Data Frame Missing Count
MS. 41Data Modulation Monitor Retrain Remote
Count
MS. 42Data Protocol Call Tx Data Compressibility
Metric
MS. 43Data Protocol Call Rx Data Compressibility
Metric
MS. 44Data Protocol Call Tx Data Metric
MS. 45Data Protocol Call Rx Data Metric
MS. 46V.PCM Digital Attenuation
MS. 47V.PCM Robbed Bit Mask
MS. 48V.PCM Coding Law
Table V. Modem Parameters
Reference # Function
MP. 0Omc Data Modulation Originate Enable
MP. 1Dial Billing Delay Duration
MP. 2Omc Data Modulation/Data Protocol
Duration
MP. 18Digital Data Modes
MP. 19Pump Data Modes
MP. 20Pump Tone Transmit Level
MP. 21Pump Transmit Level
MP. 22Pump V.34 Transmit Level
MP. 23Data Modulation Carrier Detect Duration
MP. 24Data Modulation Carrier Loss Disconnect
Timer Duration
MP. 25Data Modulation Line Quality Monitor Mode
MP. 26Data Modulation Options Mask
MP. 27Data Modulation V.32 Rate Enable Mask
MP. 28Data Modulation V.34 Data Rate Mask
MP. 29V.PCM Maximum Power
MP. 30V.PCM Reference Point
MP. 31K56 RBS Maximum
MP. 32K56 Tx Data Rate Maximum
MP. 33K56 Tx Data Rate Minimum
MP. 34DTE Interface Big Endian
MP. 35PPP Rx Mode Enable
MP. 36PPP Tx Mode Enable
MP. 37f
MP. 38f
MP. 39fP PPP Tx ACCM
PPP Detect Enable
P
PPP Rx ACCM
P
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ADSP-21mod970-110
WARNING!
ESD SENSITIVE DEVICE
ORDERING GUIDE
Package
Part NumberDescriptionProcessor ClockPackage DescriptionOption
ADSP-21mod970-110 with312 MIPS DSP with Modem
Unit Software LicenseSoftware Unit License26.0 MHz304 Plastic Ball Grid ArrayBP-304
RELATED DOCUMENTS
For further information see the ADSP-21mod970 Multiport Internet Gateway Processor data sheet.
ESD SENSITIVITY
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection. Although
the ADSP-21mod970-110 features proprietary ESD protection circuitry, permanent damage may
occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality.
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ADSP-21mod970-110
0.100 (2.54)
0.092 (2.33)
0.083 (2.12)
NOTE
THE ACTUAL POSITION OF THE BALL POPULATION IS WITHIN 0.011 (0.30)
OF ITS IDEAL POSITION RELATIVE TO THE PACKAGE EDGES. THE
ACTUAL POSITION OF EACH BALL IS WITHIN 0.004 (0.10) OF ITS IDEAL
POSITION RELATIVE TO THE BALL POPULATION.