Signal requirements

The data setup and hold requirements and switching thresholds for ARM RVT are:

Show/hideData setup and hold

The following figure and table show the setup and hold timing of the trace signals with respect to TRACECLK.

Figure 20. Data waveforms

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Table 7. Data setup and hold

ParameterRVT1RVT2Description
Tsh (min)2.0ns1.0nsData setup high
Thh (min)1.0ns1.0nsData hold high
Tsl (min)2.0ns1.0nsData setup low
Thl (min)1.0ns1.0nsData hold low

Note

RVT supports half-rate clocking mode. Data is output on each edge of the TRACECLK signal and TRACECLK (max) <= 125MHz for RVT1, and <=240MHz for RVT2.

Show/hideSwitching Thresholds

The RVT probe senses the target signaling reference voltage (VTref) and automatically adjusts its switching thresholds to VTref/2. For example, on a 3.3 volt target system, the switching thresholds are set to 1.65 volts.

Show/hideHot-plugging

If both RVT and the target are powered, plugging or unplugging the trace cable does not damage or crash the RVT system. It is not possible, however, to guarantee similar immunity to any third party target system. You must, therefore, take precautions such as pulling inputs and driving or making high Z outputs when Vsupply is not present.

Show/hideSee also

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