Microchip Technology ATSTK504

Overview

ATSTK504 from Atmel Corporation is a top-module evaluation board designed to extend the STK500 development system for 100-pin TQFP AVR microcontrollers with integrated LCD controllers, including ATmega3290 (pre-programmed), ATmega6490, ATmega3250, and ATmega6450. It provides on-board 32kHz crystal, HF crystal socket, ZIF socket, JTAG connector, LCD glass (160-segment), and port connectors for PORTE/F/G/H/J.

For engineers reviewing the ATSTK504 datasheet, ATSTK504 pinout, ATSTK504 application, or ATSTK504 equivalent, this kit supports rapid prototyping of LCD-driven embedded systems, in-system programming via ISP/High-Voltage/JTAG, real-time clock validation, and peripheral interface testing using dedicated port headers and configurable clock routing.

Technical Context

The ATSTK504 operates as a hardware extension module-not a standalone board-and requires mating with the STK500 base unit. It routes clock signals (EXT, LF=32.768kHz, HF=external crystal) directly to the AVR's XTAL/TOSC pins via a three-position switch, enabling precise clock source selection for fuse configuration and RTC validation.

All I/O access is provided through standardized 10-pin headers (PORTE, PORTF, PORTG, PORTH, PORTJ), each supplying signal lines plus VTARGET and GND. The on-board LCD interface uses a 44-lead flat cable between AVR SEGMENT PINS and LCD PINS connectors, mapping 160 segments across four COM lines per the ATmega3290 LCD controller architecture.

Key Specifications

Availability

ATSTK504 is available at Aetrix Electronics and suitable for LCD-based embedded prototyping, AVR microcontroller evaluation, and real-time clock development requiring stable component supply and full toolchain integration with AVR Studio 4.

Supply support for ATSTK504 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 programmable logic devices.

The ATSTK504 belongs to Atmel's STK500 ecosystem and was engineered specifically to accelerate development of LCD-integrated AVR applications-enabling rapid validation of segment drivers, clock tree configuration, and peripheral I/O routing without custom PCB design.

FAQ

What is the primary function of the ATSTK504 in the STK500 development system?

The ATSTK504 serves exclusively as a top-module expansion card for the STK500 base unit, adding hardware support for 100-pin TQFP AVR microcontrollers with built-in LCD controllers. It does not operate independently-it relies on STK500 for power, programming voltage, and communication interfaces. The ATSTK504 enables direct evaluation of LCD segment driving, clock source switching (LF/HF/EXT), and multi-port I/O access via dedicated headers.

Which microcontrollers are confirmed compatible with the ATSTK504, and what is included out-of-box?

The ATSTK504 is confirmed compatible with ATmega3290, ATmega6490, ATmega3250, and ATmega6450-all in 100-pin TQFP packages. The kit ships with a pre-programmed ATmega3290 device running a demonstration application that drives the on-board 160-segment LCD. No additional MCU is supplied beyond this pre-flashed sample.

How does the clock switch on the ATSTK504 affect AVR operation, and what fuse settings are required?

The ATSTK504 clock switch selects between EXT (clock from STK500), LF (on-board 32.768kHz crystal), and HF (user-installed crystal). The selected source feeds the AVR's XTAL1/TOSC1 pins. Correct fuse configuration-specifically CKSEL and SUT bits-must match the chosen clock source; for example, LF mode requires CKSEL=0010 (Low-frequency Crystal) per ATmega3290 datasheet. Fuse settings are programmed separately via ISP, HV, or JTAG.

Can the ATSTK504 be used without the STK500 base unit?

No-the ATSTK504 has no onboard power regulation, USB interface, or programming circuitry. It lacks voltage generation, reset control, and ISP/JTAG signal conditioning. All functionality-including power delivery, target voltage (VTARGET), programming signals (MOSI/MISO/SCK/RESET), and JTAG clock-is sourced from the STK500. Mounting alignment (EXPAND0/EXPAND1) and electrical interconnection depend entirely on the STK500 base.

What LCD-related hardware and documentation does the ATSTK504 provide for developers?

The ATSTK504 includes a physical 160-segment LCD glass, two dedicated 44-pin connectors (LCD PINS and AVR SEGMENT PINS), and a flat cable for interconnection. Full technical documentation is provided: Appendix B specifies exact pin-to-segment mapping, COM/SEG assignments, and LCD DDR register layout aligned to ATmega3290 memory-mapped LCD registers. This enables accurate initialization and segment control in firmware.