Intel® PXA255 Processor Developer’s Manual 2-1
System Architecture 2

2.1 Overview

The PXA255 processor is an integrated system-on-a-chip microprocessor for high performance,
low power portable handheld and handset devices. It incorporates the Intel® XScale™
microarchitecture with on-the-fly frequency scaling and sophisticated power management to
provide industry leading MIPs/mW perform a nc e . The PXA255 processor is ARM* Architecture
Version 5TE instruction set compliant (excluding floating point instructions) and f ollows the
ARM* programmer’s model.
The processor’s memory interface supports a variety of memory types to allow design flexibili ty.
Support for the connection of two companion chips permits a glu eless i nterf ace to extern al devi ces.
An integrated LCD display controller provides support for displays up to 640x480 pixels, and
permits 1-, 2-, 4-, and 8-bit grayscale and 8- or 16-bit color pixels. A 256entry/512 byte palette
RAM provides flexibility in color mapping.
A set of serial devices and general system resources provide computational and connectivity
capability for a variety of applications. Refe r to Figure2-1 for an overview of the microprocessor
system architecture.