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ABSTRACT
The enactment of very stringent safety and emissions
regulations and the need for better fuel economy and
greater functionality are driving the demand for higher
performance in embedded microcontrollers targeted for
the automotive electronics space.
The paper will examine a flexible new 32-bit core that
addresses the three key challenges involved in the
design of embedded automotive systems: how to
maintain upward compatibility with existing cores while
improving performance; how to strengthen a system so
as to reduce the impact of software bugs on its stability;
and how to support single and multi-core architectures.
INTRODUCTION
The enactment of very stringent safety and emissions
regulations and the need for better fuel economy and
greater functionality are driving the demand for higher
performance in embedded microcontrollers targeted for
the automotive electronics space. Increasing a
microcontroller’s clock rate is not sufficient enough to
meet this performance requirement, due to the nearly
linear increase in power and heat dissipation needed to
handle increases in the operating frequency.
In addition, higher performance demands greater
software complexity. Software can be obtained from
multiple internal or third-party sources, so testing and
verification are critical to confirm that all of the pieces
work together. As software complexity increases, more
stringent measures must be taken to protect a system
from software flaws.
THE CHALLENGES
In an embedded application, overall performance of the
microcontroller is not only defined by the computational
performance of its CPU core, but also by its efficiency
for data handling and system management.
While CPU architectures for embedded automotive
control can vary from a very simple 4-bit microcontroller
up to 64-bit parallel processing engines, the current
spotlight for most new CPU developments are in the 32-
bit area.
Before describing the key achievements of the new CPU
core architecture introduced in this paper, it is necessary
to identify the key requirements for upcoming embedded
automotive systems. These are:
x Performance
x Reliability
x Versatility
NEED FOR SPEED—The motivation for developing a
new CPU core was driven out of the trend toward
smaller geometries and the demand for higher
performance.
One way to increase performance is to increase internal
operating frequency. By comparing typical operating
frequencies of embedded automotive microcontrollers
with on-chip memory (around 200 MHz) to the
microprocessors used in computers (2 GHz and
beyond), it becomes obvious that this option is possible
from the technical side.
2009-01-0517
Flexible CPU Architecture to Handle Single- and Multi-core Applications
in Embedded Automotive Systems
Jens Eltze
NEC Electronics America, Inc.
*9-2009-01-0517*
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