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Oscillator sources, Reset circuit – Renesas R8C/25 User Manual

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Option Link Settings

Reference

Function

Fitted

Alternative (Removed)

Related To

R64

CAN

Do not use CAN function,

R8C/25 Microcontroller do not

have CAN function

Do not use CAN function,

R8C/25 Microcontroller do not

have CAN function

R66

CAN

Do not use CAN function,

R8C/25 Microcontroller do not

have CAN function

Do not use CAN function,

R8C/25 Microcontroller do not

have CAN function

Table 6-5: Option Links

6.7.Oscillator Sources

A crystal oscillator is fitted on the RSK and used to supply the main and sub clock input to the Renesas microcontroller.

Table 6-6: Oscillators / Resonators

details the oscillators that are fitted and alternative footprints provided on this RSK:

Component

Crystal (X1)

Fitted

20 MHz (HC/49U package)

Sub clock (X2)

Fitted

32.768 kHz (90SMX package)

Table 6-6: Oscillators / Resonators

6.8.Reset Circuit

The CPU Board includes a simple latch circuit that links the mode selection and reset circuit. This provides an easy method for swapping

the device between Boot Mode, User Boot Mode and User mode. This circuit is not required on customers boards as it is intended for

providing easy evaluation of the operating modes of the device on the RSK. Please refer to the hardware manual for more information

on the requirements of the reset circuit.

The Reset circuit operates by latching the state of the boot switch on pressing the reset button. This control is subsequently used to

modify the mode pin states as required.

The mode pins should change state only while the reset signal is active to avoid possible device damage.

The reset is held in the active state for a fixed period by a pair of resistors and a capacitor. Please check the reset requirements carefully

to ensure the reset circuit on the user’s board meets all the reset timing requirements.

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