Renesas IE850A User Manual page 13

E2, IE850A
2.3.4 Connecting the RESET pin
While you are using the E2 emulator, pin 13 (RESET pin) of the 14-pin connector must be connected to the
reset pin of the target device. An example is shown in the figure below.
The E2 emulator fixes the RESET pin to the low level before the debugger or RFP is activated. After the
debugger or RFP is activated, the emulator either keeps the pin at the low level or places it in the high-
impedance state in accord with the operation of the debugger or RFP.
Output of the reset circuit should be either n-channel open drain or be a signal generated solely by a
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resistor and capacitor (and possible other components).
Use the power source for the power domain of the RESET pin of the target device as the destination
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voltage for pulling up.
Pin 13 (RESET) of the E2 emulator is pulled up (by a 100-kΩ resistor) within the emulator (refer to chapter
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6, Internal Circuit of the E2 Emulator).
The RESET pin of the target device may be pulled up or down within the device. On this point, refer to the
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user's manual for the target device.
The maximum sink current accepted by the RESET pin of the E2 emulator is 2 mA. Select an appropriate
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pull-up resistance which does not surpass this value.
Adjust the time constant of the reset circuit so that the time elapsing before the signal reaches 80% of the
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high level from the low level is within 900 µs.
When you use hot plug-in, consider installation of a capacitor between the reset signal and GND in order to
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suppress a noise. In this case, however, the specifications of the time described above must be satisfied.
R20UT4140EJ0300 Rev.3.00
Oct.09.20
Figure 2-6 Example of Connecting a Reset Circuit
2. Connecting the Emulator and User System
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