GX1 Datasheet, PDF (2/247 Pages) National Semiconductor (TI) – Processor Series Low Power Integrated x86 Solution

While the x86 core provides maximum compatibility with
the vast amount of Internet content available, the intelligent
integration of several other functions, such as audio and
graphics, offers a true system-level multimedia solution.
The Geode GX1 processor core is a proven x86 design
that offers competitive performance. It contains integer and
floating point execution units based on sixth-generation
technology. The integer core contains a single, five-stage
execution pipeline and offers advanced features such as
operand forwarding, branch target buffers, and extensive
write buffering. Accesses to the 16 KB write-back L1 cache
are dynamically reordered to eliminate pipeline stalls when
fetching operands.
In addition to the advanced CPU features, the GX1 proces-
sor integrates a host of functions typically implemented
with external components. A full function graphics acceler-
ator contains a VGA (video graphics array) controller, bit-
BLT engine, and a ROP (raster operations) unit for
complete GUI (Graphical User Interface) acceleration
under most operating systems. A display controller con-
tains additional video buffering to enable >30 fps MPEG1
playback and video overlay when used with a National
Semiconductor Geode I/O or graphics companion chip
(e.g., CS5530 or CS9211). Graphics and system memory
accesses are supported by a tightly coupled SDRAM con-
troller which eliminates the need for an external L2 cache.
A PCI host controller supports up to three bus masters for
additional connectivity and multimedia capabilities.
The GX1 processor also incorporates Virtual System
Architecture^® (VSA™) technology. VSA technology
enables the XpressGRAPHICS and XpressAUDIO sub-
systems. Software handlers are available that provide full
compatibility for industry standard VGA and 16-bit audio
functions that are transparent at the operating system level.
Together the National Semiconductor I/O companion and
GX1 processor Geode devices provide a scalable, flexible,
low-power, system-level solution well suited for a wide
array of information appliances ranging from hand-held
personal information access devices to digital set-top
boxes and thin clients.
Features
General Features

Packaging:
— 352-Terminal Ball Grid Array (BGA) or
— 320-Pin Staggered Pin Grid Array (SPGA)

0.18-micron four layer metal CMOS process

Split rail design:
— Available 1.6V, 1.8V, or 2.0V core
— 3.3V I/O interface

Fully static design

Low Typical Power Consumption:
— 0.8W @ 1.6V/200 MHz
— 1.2W @ 2.0V/300 MHz
Note:
Typical power consumption is defined as an aver-
age, measured running Windows at 80% Active
Idle (Suspend-on-Halt) with a display resolution of
800x600x8 bpp @ 75 Hz.

Speeds offered up to 300 MHz

Unified Memory Architecture
— Frame buffer and video memory reside in main
memory
— Minimizes PCB (Printed Circuit Board) area require-
ments
— Reduces system cost

Compatible with multiple Geode I/O companion devices
provided by National Semiconductor
32-Bit x86 Processor

Supports Intel’s MMX instruction set extension for the
acceleration of multimedia applications

16 KB unified L1 cache

Six-stage pipelined integer unit

Integrated Floating Point Unit (FPU)

Memory Management Unit (MMU) adheres to standard
paging mechanisms and optimizes code fetch perfor-
mance:
— Load-store reordering gives priority to memory reads
— Memory-read bypassing eliminates unnecessary or
redundant memory reads

Re-entrant System Management Mode (SMM)
enhanced for VSA technology
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