This part is a kind of semiconductor called AT91SAM7S256.

Function of this product has AT91 ARM THUMB-BASED MICROCONTROLLERS.

Manufacturers : ATMEL Corporation

Image and pinout :

Some of the text within the PDF file :

AT91SAM ARM-based Flash MCU SAM7S512 SAM7S256 SAM7S128 SAM7S64 SAM7S321 SAM7S32 SAM7S161 SAM7S16 Features • Incorporates the ARM7TDMI® ARM® Thumb® Processor – High-performance 32-bit RISC Architecture – High-density 16-bit Instruction Set – Leader in MIPS/Watt – EmbeddedICE™ In-circuit Emulation, Debug Communication Channel Support • Internal High-speed Flash – 512 Kbytes (SAM7S512) Organized in Two Contiguous Banks of 1024 Pages of 256 Bytes (Dual Plane) – 256 Kbytes (SAM7S256) Organized in 1024 Pages of 256 Bytes (Single Plane) – 128 Kbytes (SAM7S128) Organized in 512 Pages of 256 Bytes (Single Plane) – 64 Kbytes (SAM7S64) Organized in 512 Pages of 128 Bytes (Single Plane) – 32 Kbytes (SAM7S321/32) Organized in 256 Pages of 128 Bytes (Single Plane) – 16 Kbyte [ ... ]

AT91SAM7S256 PDF Datasheet Download