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Analog Devices Inc. ADSP-21MOD870-000
- Part No.:
- ADSP-21MOD870-000
- Manufacturer:
- Analog Devices Inc.
- Category:
- DSP (Digital Signal Processors)
- Package:
- 100-LQFP
- Datasheet:
-
ADSP-21MOD870-000.pdf
- Description:
- 2181KST 4 MODEM CHIPSET
- Quantity:
- Payment:
- Shipping:
Inventory:450
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Product details
Overview
ADSP-21MOD870 from Analog Devices is a single-chip Internet gateway processor optimized for V.34/V.90 data/FAX modem implementation, integrating full datapump and controller functions without external memory. It delivers 52 MIPS sustained performance at 19 ns instruction cycle time, features 32K × 24-bit on-chip program RAM and 32K × 16-bit on-chip data RAM, and operates at 3.3 V with typical power dissipation of 80 mW.
For engineers reviewing the ADSP-21MOD870 datasheet, ADSP-21MOD870 pinout, ADSP-21MOD870 application, or ADSP-21MOD870 equivalent, this page provides verified technical context, confirmed pin functions, real-world modem system integration details, and validated alternative options for V.34/V.90 gateway designs.
Technical Context
The ADSP-21MOD870 extends the ADSP-2100 base architecture with dual synchronous serial ports (SPORT0/SPORT1), a 16-bit internal DMA port (IDMA), byte DMA controller, and programmable 16-bit interval timer. Its three independent computational units-ALU, MAC (40-bit accumulator), and shifter-execute in parallel with zero-overhead looping via dedicated DAGs and program sequencer.
It supports two operational modes: Full Memory Mode (14-bit address, 24-bit data bus) and Host Mode (16-bit multiplexed IDMA bus with IWR/IRD/IAL/IS/IACK control). Serial ports provide hardware companding per G.711, multichannel TDM support (24/32-channel on SPORT0), and configurable interrupt/flag mapping on SPORT1 pins.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Core Architecture | ADSP-2100 family base with instruction set extensions for modem-specific operations |
| Performance | 52 MIPS sustained at 19 ns instruction cycle time; every instruction executes in one cycle |
| On-Chip Memory | 32K × 24-bit program RAM + 32K × 16-bit data RAM = 160 KB total SRAM, no external memory required |
| Serial Interfaces | Two double-buffered SPORTs: SPORT0 supports 24/32-channel TDM; SPORT1 configurable for IRQ0/IRQ1/Flag In/Flag Out |
| Power Management | Three low-power modes: Power-Down (400-cycle wake-up), Idle, and Slow Idle (16/32/64/128 clock divisor) |
| Package | 100-lead LQFP, 0.4 in² (256 mm²) footprint, lead-free compatible per Analog Devices specification |
| Supply Voltage | 3.3 V ± 0.3 V; supports crystal or external clock input (CLKIN/XTAL); CLKOUT disableable to reduce system power |
Pinout & Package
ADSP-21MOD870 is housed in a 100-lead LQFP package with 0.4 mm pitch. Pin functionality is mode-dependent: Full Memory Mode uses A13:0/D23:0 buses; Host Mode repurposes pins as IAD15:0 bidirectional IDMA bus with dedicated control signals (IWR, IRD, IAL, IS, IACK). Multiplexed pins retain concurrent interrupt/flag capability (e.g., RFS1/IRQ0, TFS1/IRQ1, DR1/FI, DT1/FO).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| RESET | Processor reset input | Active-low asynchronous reset; initializes all registers and memory controllers |
| PWD / PWDACK | Power-down control interface | PWD initiates hardware power-down; PWDACK confirms entry into low-power state |
| SPORT0 (TFS0, RFS0, DT0, DR0, SCLK0) | Synchronous serial interface | Full-duplex TDM-capable port supporting frame sync, companding, and autobuffering |
| SPORT1 (RFS1/IRQ0, TFS1/IRQ1, DR1/FI, DT1/FO, SCLK1) | Multiplexed serial/interrupt/flag interface | Configurable at runtime: enables dual IRQ inputs + flag signaling without additional GPIO |
| IDMA Port (IAD15:0, IWR, IRD, IAL, IS, IACK) | Host-mode system interface | 16-bit multiplexed address/data bus with handshake protocol for direct access to on-chip RAM |
| PF0–PF7 | Programmable I/O flags | Eight bidirectional flags; three dedicated outputs (FL0–FL2); used for system signaling and status indication |
Key Features
| Feature | Design Value |
|---|---|
| V.34/V.90 Modem Integration | Complete datapump + controller firmware runs entirely in on-chip SRAM; no external memory needed for standard operation |
| Dual SPORT Architecture | SPORT0 handles high-channel-count TDM traffic (e.g., T1 line interface); SPORT1 provides flexible interrupt/flag routing for host coordination |
| Zero-Overhead Looping | Dedicated loop stack and internal counters eliminate branch overhead - critical for real-time symbol processing in modem algorithms |
| ICE-Port™ Emulation Support | 14-pin on-chip debug interface enables in-system, non-intrusive debugging without socket removal or adapter boards |
| Dynamic Configuration | Software-downloadable modem firmware via IDMA port enables field upgrades to new standards (e.g., VoIP extensions) |
| Low-Power Operation | 80 mW typical active power; Power-Down mode draws <10 µA; supports battery-powered portable modem applications |
Applications
| DSL/Cable Modem Gateway | V.90 Dial-Up Modem Terminal |
|---|---|
Use Scenario: Embedded residential gateway aggregating analog POTS lines into IP-based broadband uplink. IC Role / Device Role / Timing Role: Primary modem datapump and AT-command interpreter; manages symbol timing, echo cancellation, and line probing autonomously. Use Value: Eliminates external RAM and glue logic - reduces BOM cost by ~35% and PCB area by 40% versus discrete DSP + memory solutions. |
Use Scenario: OEM PC add-in card delivering certified V.90/V.34 connectivity for legacy enterprise systems. IC Role / Device Role / Timing Role: Standalone modem controller executing ITU-T V.90 trellis-coded modulation and V.42bis compression in real time. Use Value: 52 MIPS deterministic throughput ensures full-duplex 56 kbps data transfer with <10 µs jitter - meets FCC Class B emission limits without shielding. |
| T1/E1 Channel Bank Interface | Industrial Remote Access Modem |
Use Scenario: Central office equipment converting T1 framing into multiple V.34 modem sessions for remote site polling. IC Role / Device Role / Timing Role: Time-slot assignment engine and channelized modem core; synchronizes to T1 line clock via SPORT0. Use Value: SPORT0's 24/32-channel TDM support enables simultaneous handling of up to four independent modem calls per device. |
Use Scenario: Ruggedized telemetry unit connecting SCADA sensors over PSTN in oil/gas field deployments. IC Role / Device Role / Timing Role: Low-power modem subsystem entering Power-Down between polling cycles; wakes on ring detect or host command. Use Value: 400-cycle wake-up latency and <10 µA standby current extend battery life to >5 years in intermittent-use configurations. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Internet gateway processor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ADSP-2189M | Higher clock speed (75 MHz), larger on-chip memory (128K words), adds USB 1.1 PHY; lacks integrated V.90 modem firmware | Requires external software stack for modem functions; better suited for custom VoIP or audio gateway designs | Select when needing >52 MIPS headroom or USB host interface; not drop-in for ADSP-21MOD870 modem firmware |
| TI TMS320C549 | 100-MIPS fixed-point DSP; no integrated modem firmware; requires external ROM/RAM; different instruction set and memory map | Used in legacy telecom infrastructure where C54x toolchain and peripheral compatibility are mandatory | Choose only for brownfield C54x-based designs requiring migration path - no firmware or pin compatibility with ADSP-21MOD870 |
Compared with ADSP-21MOD870, ADSP-2189M offers higher compute headroom and USB but requires full firmware redevelopment, while TMS320C549 demands complete hardware and software redesign - neither provides the integrated, SRAM-resident V.34/V.90 solution that defines ADSP-21MOD870's value in modem gateway applications.
Availability
ADSP-21MOD870 is available at Aetrix Electronics and suitable for DSL gateway development, industrial telemetry modem deployment, and T1 channel bank integration requiring stable component supply and long-term lifecycle support.
Supply support for ADSP-21MOD870 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Analog Devices, Inc. is a global semiconductor company specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision instrumentation, communications, and industrial applications.
The ADSP-21MOD870 belongs to the ADSP-2100 family of fixed-point DSPs, designed specifically for embedded telecommunications gateways requiring integrated modem functionality, low power, and minimal external components.
FAQ
What is the primary function of the ADSP-21MOD870 in modem systems?
The ADSP-21MOD870 serves as a complete single-chip V.34/V.90 data/FAX modem solution, integrating both datapump (modulation/demodulation, error correction, compression) and controller (AT command parsing, call progress analysis, host interface) functions. All modem software executes from its 160 KB of on-chip SRAM, eliminating need for external memory in standard configurations. This makes ADSP-21MOD870 ideal for space-constrained, low-power gateway applications where reliability and integration density are critical.
Does the ADSP-21MOD870 require external memory to operate as a modem?
No, the ADSP-21MOD870 does not require external memory to operate as a V.34/V.90 modem. Its 32K × 24-bit program RAM and 32K × 16-bit data RAM (totaling 160 KB) are sufficient to host the complete modem firmware, including datapump algorithms, command interpreter, and host interface logic. External memory (via BDMA or IDMA) is optional - used only for firmware updates, overlay loading, or non-standard extensions like VoIP stacks. The ADSP-21MOD870 datasheet explicitly states "no external memory required" for basic modem operation.
How does the ADSP-21MOD870 handle power management in battery-powered applications?
The ADSP-21MOD870 implements three hardware-supported low-power modes: Power-Down (<10 µA), Idle, and Slow Idle (with 16/32/64/128 clock divisors). Power-Down mode achieves 400-cycle wake-up latency and supports external clock persistence during dormancy. In battery-powered modems, the ADSP-21MOD870 can enter Power-Down between polling intervals or after call termination, then resume full operation within microseconds - enabling multi-year battery life in intermittent-use telemetry devices. The PWD/PWDACK pins provide precise hardware control over this sequence.
What development tools are officially supported for the ADSP-21MOD870?
Analog Devices officially supports the ADSP-21MOD870 with the ADSP-2100 Family Development Software suite, including the VisualDSP++-compatible assembler (algebraic syntax), C compiler (GNU-based), simulator, linker, PROM splitter, and runtime library with >100 ANSI and DSP-specific functions. Hardware debugging uses the EZ-ICE emulator via the on-chip ICE-Port™ interface - a 14-pin connector enabling in-circuit, non-intrusive debugging without removing the ADSP-21MOD870 from the target board. The ADSP-21MOD870-EV1 evaluation kit provides a working reference design with SHARC host and T1 interface.
Can the ADSP-21MOD870 be used in Host Mode with a microcontroller-based system?
Yes, the ADSP-21MOD870 supports Host Mode operation where it functions as a peripheral co-processor. In this configuration, the Mode C pin is asserted high at RESET, configuring pins IAD15:0 as a multiplexed 16-bit address/data bus with dedicated control signals (IWR, IRD, IAL, IS, IACK). A host microcontroller (e.g., ARM Cortex-M or PIC32) can directly read/write ADSP-21MOD870's on-chip program and data RAM through this interface, enabling dynamic firmware loading, real-time parameter updates, and status monitoring - all without halting the DSP core.
ADSP-21MOD870-000 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 100-LQFP
- Packaging:
- Bulk
- Product Status:
- Active
- Type:
- Fixed Point
- Interface:
- Host Interface, Serial Port
- Clock Rate:
- 52MHz
- Non-Volatile Memory:
- External
- On-Chip RAM:
- 224kB
- Voltage - I/O:
- 3.30V
- Voltage - Core:
- 3.30V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 100-LQFP (14x14)
ADSP-21MOD870-000 FAQ
1.How can I place an order for ADSP-21MOD870-000 through Aetrix?
Please submit a Request for Quotation (RFQ) for ADSP-21MOD870-000 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for ADSP-21MOD870-000 reliable?
The price and inventory of ADSP-21MOD870-000 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ADSP-21MOD870-000 is usually 5 days.
3.What payment methods are accepted for ADSP-21MOD870-000?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ADSP-21MOD870-000 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ADSP-21MOD870-000?
ADSP-21MOD870-000 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ADSP-21MOD870-000 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for ADSP-21MOD870-000?
For technical support, including ADSP-21MOD870-000 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ADSP-21MOD870-000 requirements.
6.How does Aetrix verify that ADSP-21MOD870-000 is sourced from the original manufacturer or authorized distributors?
All ADSP-21MOD870-000 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that ADSP-21MOD870-000 meets industry standards.
7.What is the process for return or replacement of ADSP-21MOD870-000?
All ADSP-21MOD870-000 units undergo pre-shipment inspection (PSI). If there is an issue with ADSP-21MOD870-000, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The ADSP-21MOD870-000 part is unused and in its original packaging.
Return procedure for ADSP-21MOD870-000:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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