TECH REPORT
T
he past few decades have brought about unprecedented advancements in semiconductor
technology. However, with each advance in semiconductor technology, new obstacles to maintaining the exponential improvement of process technology arise.
Cosmic Rays dispersed by the atmosphere Source CERN
Today, CMOS technology has shrunk to such a size that extraterrestrial radiation and chip packaging cause failures at an increasing rate. Since these errors are temporary, they are called soft errors. The
A SOFT-ERROR IS A CHANGE OF STATE
first instance of soft errors was in 1978,
INDUCED BY AN
when Intel was unable to deliver its chips
ENERGETIC PARTICLE.
to AT&T due to uranium-contaminated packaging modules. Intel, while coining the
HOWEVER, UNLIKE
term “soft fail,” reported that radioactive
A HARD ERROR, THE
contamination could cause not only flips in
AFFECTED DEVICE’S
stored data, but also microcontroller lockup. At Cypress Semiconductor, we came
NORMAL OPERATION
across the first instance of soft errors in
CAN BE RESTORED
2001, when a large telecommunications
BY A SIMPLE RESET/
client found that a single soft error in an SRAM was causing hundreds of computers
REWRITE OPERATION.
in a system farm to crash.
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