D.1. Overview of high-speed design

Failure to observe high-speed design rules when designing a target system containing an ARM Embedded Trace Macrocell (ETM) trace port can result in incorrect data being captured by RealView Trace.You must give serious consideration to high-speed signals when designing the target system.

The signals coming from an ARM ETM trace port can have very fast rise and fall times, even at relatively low frequencies. For example, a signal with a rise time of 1ns has an effective knee frequency of 500MHz and a signal with a rise time of 500ps has an effective knee frequency of 1GHz (fknee = 0.5/Tr).

Note

These principles apply to all of the trace port signals, but special care must taken with TRACECLK.

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