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Why troubles occur when a program that run normally run on emulator MCU?

Latest Updated:03/13/2008

Question:

(Clock)  The problems below occurred when a program which runs normally on an actual MCU was run on an emulator MCU. Are these problems specific to the emulator MCU, or does operation differ according to ROM type (Mask ROM, Flash Memory, QzROM, etc.)?
(i) There is about 10-20 seconds of delay while connecting to the ICE.
(ii) When the oscilloscope probe touches the Xcin/Xcout pin, oscillation stops. [2008/03/13]

Answer:

(i) The delay is caused by the wait for the crystal resonator to stabilize before connecting to the emulator MCU.
(ii) If the probe that directly touches the Xcin/Xcout pin is not low capacitance, depending on its capacitance it may interfere with (stop) oscillation.

Even within the same MCU Group, there are products of different ROM types (eg. Mask ROM, Flash Memory, QzROM) and memory capacity, and among emulator MCUs, oscillation characteristics as well as field values of electrical characteristics such as characteristic values, operating margins, and noise resistance/radiation capacity may vary. You must confirm the optimal oscillation circuit parameters applicable to your systems or products with the oscillator manufacturer in advance.

(#106880)

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