Analog Devices Inc. ADSP-2185LBST-133

Overview

ADSP-2185LBST-133 from Analog Devices is a 33 MIPS fixed-point DSP microcomputer optimized for real-time digital signal processing in audio, telecom, and industrial control systems. It integrates 16K × 24-bit on-chip program RAM, 16K × 16-bit on-chip data RAM, dual SPORTs with hardware companding, a 16-bit internal DMA port, and operates at 30 ns instruction cycle time (133 MHz CLKIN → 33 MHz core).

For engineers reviewing the ADSP-2185LBST-133 datasheet, ADSP-2185LBST-133 pinout, ADSP-2185LBST-133 application, or ADSP-2185LBST-133 equivalent, key selection criteria include its 100-pin TQFP package, power-down recovery in ≤100 CLKIN cycles, zero-overhead looping, dual operand fetch per cycle, and ICE-Port™ debug interface compatibility.

Technical Context

The ADSP-2185LBST-133 implements the ADSP-2100 family base architecture with three independent computational units (ALU, MAC, shifter), two dedicated DAGs, and a zero-overhead program sequencer supporting conditional jumps and subroutine calls in one cycle. Its 3-bus architecture enables simultaneous dual operand fetches - one from program memory and one from data memory - within every instruction cycle.

It supports two operating modes: Full Memory Mode (14-bit address, 24-bit data bus) and Host Mode (16-bit multiplexed IDMA bus), selected via Mode C pin at reset. Serial ports SPORT0 and SPORT1 are software-configurable for synchronous serial I/O, multichannel TDM, or reassignment to IRQ/flag functions, with hardware A-law/µ-law companding per CCITT G.711.

Key Specifications

Pinout & Package

ADSP-2185LBST-133 is housed in a 100-lead thin quad flat pack (TQFP) with 0.5 mm pitch, thermally enhanced for sustained 33 MIPS operation. Pin functionality is partially multiplexed: external bus pins are configured at RESET; SPORT/flag/interrupt pins are software-reconfigurable during runtime.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed-point DSP microcomputer applications.

Compared with ADSP-2185LBST-133, ADSP-2189MKSTZ-133 offers superior debug depth without layout changes, while TMS320C549PGE trades integrated peripherals for higher peak throughput and different toolchain dependencies - making ADSP-2185LBST-133 optimal for cost-sensitive, audio- and control-focused embedded DSP designs with tight PCB area constraints.

Availability

ADSP-2185LBST-133 is available at Aetrix Electronics and suitable for audio signal processing, telecom line card design, industrial motor control, and test & measurement instrumentation requiring stable component supply across long-lifecycle industrial programs.

Supply support for ADSP-2185LBST-133 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 leader in high-performance analog, mixed-signal, and DSP technology, headquartered in Norwood, MA, with over 50 years of innovation in precision signal processing components.

The ADSP-21xx family - including ADSP-2185LBST-133 - was designed specifically for cost-sensitive, low-power embedded DSP applications demanding real-time determinism, on-chip memory integration, and minimal external interface complexity.

FAQ

What clock frequency does ADSP-2185LBST-133 require to achieve its rated 33 MIPS performance?

ADSP-2185LBST-133 requires a 133 MHz TTL-compatible clock applied to CLKIN (or a 133 MHz fundamental crystal across CLKIN/XTAL) to achieve its specified 30 ns instruction cycle time and 33 MIPS sustained performance. The internal core runs at half the CLKIN frequency, so 133 MHz input yields 66.5 MHz internal clock - matching the 30 ns cycle specification. Using lower frequencies reduces MIPS proportionally.

Does ADSP-2185LBST-133 support booting directly from external memory?

Yes, ADSP-2185LBST-133 supports automatic booting from byte-wide external memory such as EPROM or flash via its byte DMA port. During reset, it loads the first 64 words of program code from external memory into on-chip program RAM, then begins execution. This eliminates need for external boot ROM controllers and simplifies system initialization in ADSP-2185LBST-133-based designs.

Can the serial ports of ADSP-2185LBST-133 be used for UART-like communication?

Yes, ADSP-2185LBST-133 supports UART emulation through software reconfiguration of SPORT0 or SPORT1 - by setting appropriate bit rates, frame formats, and using internal clock generation. While not a true UART peripheral, this capability enables RS-232/422 connectivity in systems like the EZ-KIT Lite, avoiding added transceiver ICs when asynchronous serial is needed alongside synchronous audio or TDM traffic.

What is the purpose of the Mode C pin on ADSP-2185LBST-133, and how is it configured?

The Mode C pin on ADSP-2185LBST-133 selects between Full Memory Mode (Mode C = 0) and Host Mode (Mode C = 1) during reset. It is multiplexed with PF2 and must be set before reset deassertion - typically via a 100 kΩ pull-up/down resistor or active driver gated by RESET. Incorrect configuration prevents proper external bus operation, so ADSP-2185LBST-133 system design must fix Mode C prior to power-up sequencing.

How does the power-down feature of ADSP-2185LBST-133 differ from idle mode?

ADSP-2185LBST-133 power-down mode halts the internal clock and reduces supply current to microamp levels, with wake-up in ≤100 CLKIN cycles upon interrupt or PWD deassertion. Idle mode maintains clocking and permits DMA/SPORT activity but stops instruction fetch until interrupt; Slow Idle further divides the clock by 16/32/64/128. Power-down is for longest battery life; Idle is for lowest-latency responsiveness.