This document is the Atmel AT43USB325 datasheet, which introduces the features and characteristics of the product, including 8-bit RISC microcontroller, USB Hub, USB keyboard function, 16KB program memory, 512-byte data SRAM, 32x8 general-purpose working registers, 42 programmable I/O port pins, support for 20x8 keyboard matrix, keyboard scan inputs with pull-up resistor, four LED driver outputs, one 8-bit timer/counter, one 16-bit timer/counter, external and internal interrupt sources, programmable watchdog timer, 6MHz oscillator, On-chip PLL, 5V operation and On-chip 3.3V power supply
The AT43USB325 is an 8‑bit AVR® RISC microcontroller with an integrated USB hub that includes one attached function and four external ports, making it suitable for keyboard controller applications. It offers 16 KB of on‑chip program memory, 512 bytes of data SRAM, 42 programmable I/O pins, and a range of peripherals such as timers, watchdog, and LED drivers.
The document details the pin configuration, signal functions, and architectural overview, including the Harvard memory architecture, register set, and USB endpoint handling. Electrical specifications, packaging options, and ordering information are also provided.
| Instruction cycle time | 83 ns |
|---|---|
| Program memory | 16 KB |
| Data SRAM | 512 bytes |
| Package | 64‑lead LQFP |
| USB hub ports | 1 attached + 4 external |
| Operating voltage | 5 V (with on‑chip 3.3 V regulator) |
The AT43USB325E uses an SRAM that is automatically written from an external serial EEPROM during power‑on.
The integrated USB hub provides one attached function port and four external ports.
The device is offered in a 64‑lead LQFP package.
The microcontroller operates at 5 V and includes an on‑chip 3.3 V regulator.