Microchip Technology AT91EB55

Overview

AT91EB55 Evaluation Board from Atmel (now Microchip Technology) is a hardware platform for real-time development and evaluation of the AT91M55800A ARM7TDMI-based microcontroller. It integrates 256 KB SRAM, 2 MB Flash, 4 MB Serial DataFlash, dual RS-232 interfaces, ADC/DAC peripherals, JTAG debugging support, and expansion connectors for I/O and external bus interfacing - enabling rapid prototyping of embedded control and industrial monitoring applications.

For engineers reviewing the AT91EB55 datasheet, AT91EB55 pinout, AT91EB55 application, or AT91EB55 equivalent, this board serves as a validated reference design for AT91M55800A-based systems requiring on-chip debug monitor (Angel), memory-mapped peripheral access, low-power RTC operation, and configurable power measurement via JP5/JP8/JP9 jumpers.

Technical Context

The AT91EB55 implements a complete evaluation system around the AT91M55800A - a 176-pin TQFP ARM7TDMI microcontroller with integrated APMC, RTC, USARTs, SPI, ADC, DAC, PIO, and EBI. Its architecture supports remappable memory regions, boot selection via JP1, and dual-voltage domain operation (VDDIO at 3.3 V, VDDCORE configurable at 3.3 V or 2 V).

On-board resources include an Angel Debug Monitor preloaded in Flash (0x01006000–0x0100FFFF), functional test software, and boot firmware that initializes the 32 MHz master clock (PLL ×2 from 16 MHz crystal), configures EBI timing, and enables serial communication through MAX3223 transceivers. Power management allows independent current measurement of VDDIO, VDDCORE, and VDDBU domains using dedicated jumpers.

Key Specifications

Availability

AT91EB55 is available at Aetrix Electronics and suitable for embedded firmware development, ARM7-based industrial controller validation, low-power RTC system testing, and educational microcontroller labs requiring stable component supply and full documentation support.

Supply support for AT91EB55 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

Atmel Corporation - now part of Microchip Technology - is a semiconductor company specializing in microcontrollers, nonvolatile memory, and wireless solutions for industrial, automotive, and consumer applications.

The AT91EB55 belongs to Atmel's AT91 ARM-based evaluation board family, designed specifically to accelerate development for the AT91M55800A microcontroller in real-time embedded systems requiring debug visibility, memory expansion, and peripheral interface validation.

FAQ

What is the primary function of the AT91EB55 Evaluation Board?

The AT91EB55 Evaluation Board is a fully assembled hardware platform for developing, debugging, and validating firmware on the AT91M55800A ARM7TDMI microcontroller. It provides immediate access to all major peripherals - including SRAM, Flash, ADC/DAC, USARTs, JTAG, and expansion buses - allowing engineers to prototype and test real-time embedded applications without custom PCB design. The AT91EB55 includes preloaded Angel Debug Monitor and boot firmware to enable rapid code iteration.

Does the AT91EB55 support in-circuit emulation and JTAG debugging?

Yes, the AT91EB55 supports full in-circuit emulation (ICE) and JTAG boundary scan via its standard 20-pin ARM-compliant JTAG interface (P5). Strap CB15 selects between ICE debug mode (pins 1–2) and IEEE 1149.1 boundary scan mode (pins 2–3). The board also supports RTCK synchronization (CB16) and is compatible with third-party ARM debug tools. The AT91EB55 enables code download, breakpoint setting, and register inspection without consuming system memory or serial resources.

How does the AT91EB55 handle power measurement for different voltage domains?

The AT91EB55 provides isolated current measurement capability for three critical voltage domains: JP5 measures total microcontroller consumption (VDDIO + VDDCORE), JP8 isolates core supply current (VDDCORE), and JP9 enables battery backup domain measurement (VDDBU). These jumpers allow engineers to quantify power usage during active, idle, and RTC-only modes - essential for optimizing low-power firmware on the AT91M55800A. The AT91EB55 schematic (Figure 6-8) details the measurement points and recommended ammeter connections.

Can the AT91EB55 be used to evaluate low-power RTC and shutdown features?

Yes, the AT91EB55 includes dedicated hardware for evaluating low-power operation: a 32.768 kHz crystal drives the RTC, a 3 V battery (BT1) powers VDDBU, and JP9 enables VDDBU current measurement. JP7 activates APMC-controlled shutdown, and S1 serves as a wake-up button. RTC alarms can be programmed to restore power autonomously. This makes the AT91EB55 ideal for validating sleep/wake cycles, battery lifetime estimates, and real-time timestamping in energy-constrained applications using the AT91M55800A.

What memory upgrade options are supported on the AT91EB55?

The AT91EB55 supports memory upgrades via footprint compatibility: SRAM can be upgraded from 256 KB (two 128K×8 devices) to 1 MB using two 512K×8, 3.3 V, 10/15 ns parts; Serial DataFlash can scale from 4 MB to 16 MB by populating three additional AT45DB321 footprints. Flash memory mapping is configurable via JP1 to access either first or second 1 MB half - enabling safe field updates. All memory configurations are validated in the AT91EB55 User Guide (Rev. 1709C).