IAR SYSTEMS I-jet User Manual page 55

Parameter Value
Tds 0.75 ns (minimum)
Tdh 0.75 ns (minimum)
Table 22: Data setup and hold times
Important: The minimum setup and hold times in the table are not as important as the
length of the data valid time, because the logic inside the I-jet probe can delay the
TRACECLK and TRACEDATA signals as needed, up to 2.5 ns. To get the best results,
the trace valid data (Tds + Tdh) should be as long as possible. The best way to achieve
that in the MCU or ASIC, is to make sure the trace data is changed in the middle of the
High or Low DDR TRACECLK signal. This way the trace data valid time is the widest
and the data setup and hold times are the biggest for a given frequency.
Switching thresholds
I-jet Trace measures the target signals reference voltage (VTref) at the debug connector
and automatically adjusts its switching thresholds to ½ of VTref. For example, on a
3.3 V target system, the switching thresholds are set to 1.65 V.
Description
Data setup time
Data hold time
I-jet Trace
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