AT91RM3400-AU - 66MHz ARM7TDMI 256KB ROM MCU | Microchip
Teilenummer: AT91RM3400-AU ✓ AktivAT91RM3400-AU Übersicht
An ARM microcontroller is a programmable system-on-chip built around a licensed processor core, embedded memory, and dedicated peripheral controllers. The ARM7TDMI core combines a 32-bit ARM architecture with Thumb instruction support, allowing compact code to execute in the 16-bit Thumb state while retaining 32-bit processing capability. The AT91RM3400 therefore sits within the hierarchy of embedded microcontroller, embedded processor, and programmable logic device.
Three headline characteristics define this part: a 66 MHz ARM7TDMI operating frequency, 256 KB of program ROM, and a broad set of communication peripherals. Its 96 KB SRAM provides working memory for protocol stacks, buffers, and real-time control tasks. The integrated I2C, SPI, SSC, UART/USART, USB, and MMC interfaces reduce external component count and allow the controller to serve as the central communications hub for an embedded board.
The part uses the ARM7TDMI architecture with Thumb-2 instruction support for code-density benefits. Its on-chip peripheral set covers serial data exchange, storage-device access, and system monitoring through a watchdog timer. This combination is suited to legacy industrial controllers, communication gateways, data acquisition equipment, and embedded accessories where established ARM7 software support and a mature peripheral set are more valuable than a newer high-performance core.
Typical applications include USB-connected control panels, industrial serial bridges, local data concentrators, multimedia card data stores, and compact instrumentation. The 100-LQFP package provides enough pin count for parallel and serial external interfaces while remaining compatible with standard PCB assembly methods. Board designers should route USB differential pairs carefully, provide clean clock and reset networks, and decouple each supply rail close to its supply pins.
Design trade-offs center on the 66 MHz ARM7TDMI performance level and the 256 KB ROM footprint. For new designs, confirm that application code, bootloader space, and update requirements fit the available memory before committing the board layout. If substantially greater code space, faster performance, or lower power consumption is required, evaluate a newer microcontroller family and plan a software migration rather than treating a different device as a pin-compatible substitute.
This page consolidates core specifications, verified source listings, interface guidance, application fit, and drop-in replacement analysis to support faster component selection and board planning.
Drop-in-Alternativen für AT91RM3400-AU – gleiches Gehäuse, Pin-kompatibel. Bauteile mit anderem Gehäuse, die eine PCB-Überarbeitung erfordern, sind ausgeschlossen.
Für dieses Produkt sind keine Drop-in-Alternativen verfügbar.
Alternativen anfordernAT91RM3400-AU Grenzwerte & elektrische Eigenschaften
| Manufacturer | Microchip Technology |
| Product Series | AT91SAM |
| Processor Core | ARM7TDMI |
| Architecture | 16/32-bit ARM with Thumb support |
| Maximum CPU Frequency | 66 MHz |
| Program Memory | 256 KB ROM (256K x 8) |
| RAM | 96 KB |
| Gehäuse | 100-LQFP (14 x 14 mm) |
| Montageart | Surface mount |
| I2C Interface | 1 interface |
| SPI Interface | 1 interface |
| SSC Interface | 1 interface |
| UART/USART Interface | 1 interface |
| USB Interface | 1 interface |
| Multimedia Card Interface | 1 MMC interface |
| Watchdog Timer | Integrated WDT |
AT91RM3400-AU 100-lqfp (14 x 14 mm) Pinbelegungsleitfaden
Pinbelegung für AT91RM3400-AU (100-lqfp (14 x 14 mm)-Gehäuse). Dieser digitale IC umfasst GPIO, Kommunikationsschnittstellen (UART, SPI, I2C) und Versorgungspins. Alternative Pin-Funktionen und Konfigurationsoptionen entnehmen Sie dem Herstellerdatenblatt. Unverzichtbar für Embedded-System-Design und PCB-Layout.
Keine detaillierten Pinbelegungsdaten verfügbar für AT91RM3400-AU.
Siehe die Datenblatt für die vollständige Pin-Konfiguration.
Typische Anwendungen
AT91RM3400-AU ist geeignet für 6 Anwendungs: USB-Connected Industrial Control Panel, Industrial Serial Gateway, Data Acquisition and Sensor Controller, Multimedia Card Data Logger, Communications Hub with USB Backup, Legacy Peripheral Controller.
USB-Connected Industrial Control Panel
The AT91RM3400-AU fits a USB control panel that must coordinate sensors, actuators, and operator commands in a single embedded controller. Its 66 MHz ARM7TDMI core provides headroom for a real-time control task alongside USB communication, while the 256 KB ROM holds application firmware and 96 KB of RAM supports display, logging, and protocol buffers. The integrated USB, UART/USART, SPI, and I2C controllers reduce the need for separate interface devices. Design the USB path with controlled-impedance routing and a compliant transceiver arrangement, and isolate noisy actuator drive circuitry from the communications ground return.
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Industrial Serial Gateway
The AT91RM3400-AU can serve as a protocol-conversion gateway between UART/USART equipment and an upstream host interface. Its 66 MHz ARM7TDMI core can service multiple interrupt-driven serial tasks, while SPI and I2C provide local connections to sensors, transceivers, or memory devices. The 96 KB RAM is useful for frame buffering and queue management in a gateway handling short protocol bursts. Validate throughput against the slowest attached device, use interrupt-driven DMA where supported, and keep the 256 KB ROM limit in view when adding protocol stacks, diagnostics, and secure update routines.
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Data Acquisition and Sensor Controller
The AT91RM3400-AU is appropriate for a compact data-acquisition controller that gathers measurements over SPI or I2C, stores records on a multimedia card, and forwards results through UART/USART or USB. Its integrated peripheral controllers reduce external wiring and firmware overhead, while the 96 KB RAM provides buffer space for sampled data and protocol assembly. The 66 MHz core supports deterministic interrupt servicing across several buses. Pay attention to analog reference stability, digital isolation from switching nodes, and SD-card write timing, since storage transactions can momentarily reduce the margin available to real-time acquisition tasks.
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Multimedia Card Data Logger
The AT91RM3400-AU can act as a local data logger by writing records to a removable multimedia card while communicating with a host through USB or a serial interface. The dedicated MMC interface is more efficient than bit-banging storage, and the 256 KB ROM provides space for a compact firmware image with a bootloader. The 96 KB RAM can hold acquisition buffers and file-management structures, although sustained logging rates must be checked against memory and bus bandwidth. Use a power-loss-aware file system, confirm card compatibility with Microchip's recommended cards, and provide bulk decoupling around the device.
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Communications Hub with USB Backup
The AT91RM3400-AU can combine several serial links in a communications hub, using UART/USART for legacy equipment, I2C or SPI for local peripherals, and USB for a modern host connection. The ARM7TDMI core at 66 MHz supports multitasking across interrupt-driven controllers, and the 96 KB RAM supports protocol queues and routing tables. Firmware must enforce flow control and isolate buffer ownership between tasks. For production boards, test hot-plug behavior, implement robust bus-fault recovery, and route high-current USB and power interfaces away from sensitive communication returns.
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Legacy Peripheral Controller
The AT91RM3400-AU is useful for maintaining or reproducing legacy peripheral-control boards that depend on an ARM7TDMI ecosystem and established AT91SAM software. Its 256 KB ROM and 96 KB RAM fit moderate firmware sizes, while I2C, SPI, UART/USART, and MMC interfaces cover common board-level functions. The 100-LQFP package simplifies repair and replication on existing footprints when the exact pin configuration and electrical limits are confirmed. Before revision, verify whether the original board expects a boot ROM, external memory interface, or legacy peripheral mapping that is not described by the basic ordering information.
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Zusammenfassung der empfohlenen Produkte
Technische Referenzdaten für AT91RM3400-AU – Vergleich, Designhinweise und Compliance-Informationen.
Auswahlhilfe
Vergleich mit Alternativen
| Parameter | Dieses Produkt |
|---|---|
| Brand | Microchip Technology |
| Package | 100-LQFP (14 x 14 mm) |
| Processor Core | ARM7TDMI |
| Maximum CPU Frequency | 66 MHz |
| Program Memory | 256 KB ROM (256K x 8) |
| RAM | 96 KB |
| Serial Interfaces | I2C, SPI, SSC, UART/USART |
| USB Interface | Integrated USB interface |
| Storage Interface | Integrated MMC interface |
| System Monitoring | Integrated watchdog timer |
Wichtigste Unterscheidungsmerkmale
- Legacy ARM7TDMI compatibility with a broad integrated interface set (vs. AT91R40008-66AU)
- AT91SAM-family software and peripheral continuity (vs. ATMEGA644PA-AU)
- Purpose-built integration for communications and removable storage (vs. STM32F103R6T6ATR)
Designhinweise
Treat the AT91RM3400-AU as a mixed-signal embedded design even though its listed features are primarily digital. Route the 66 MHz clock as a short, continuous net away from USB, serial transceiver outputs, and MMC clock lines. Place input, output, and decoupling capacitors directly at the associated device pins, and keep the 100-LQFP escape routing dense enough to avoid long stubs between the controller and its passive components.
USB, MMC, and high-speed serial links require controlled-impedance routing rather than arbitrary point-to-point connections. Keep USB differential pairs adjacent and matched, avoid stubs and test pads that break symmetry, and provide a continuous reference plane beneath the pair. Check the device's USB operating mode and external transceiver requirements in the manufacturer documentation before finalizing the connector and protection components.
Firmware size, peripheral activity, and supply voltage determine current demand, so power budgeting must be performed for the assembled board rather than from the 66 MHz clock rating alone. Separate sensitive analog or reference routing from switching and digital return paths, verify startup current for attached loads, and confirm that the chosen regulator can support the MCU plus external interface current without violating its own thermal and stability limits.
Do not substitute an AT91R40008-66AU, ATmega644PA-AU, or STM32 device directly into an AT91RM3400-AU footprint. Differences in processor architecture, memory organization, package details, and peripheral assignments can make a seemingly compatible replacement nonfunctional. For a redesign, create a complete pin, voltage, timing, boot, and firmware migration matrix; for a like-for-like repair, use the exact orderable part number and verify its documentation revision.
Compliance-Informationen
Compliance status is not stated in the available product information. Confirm RoHS, REACH, terminal-finish, halogen, conflict-mineral, and automotive qualification documentation for the exact orderable part number before production release.
