Renesas H8SX/1648 - Manual (Page 18)

Option Link Settings
Reference Function Fitted Alternative (Removed) Related To
R235 MCU Mode MCU User Boot Mode enabled, also
can be enabled by fitting jumper in
J12
MCU User Boot mode disabled R236
R236 MCU Mode MCU Extended mode enabled, also
can be enabled by fitting jumper in
J13
MCU Extended mode disabled R235
Table 6-12: MCU mode links.
6.7. Oscillator Sources
A crystal oscillator is fitted on the RSK and used to supply the main clock input to the Renesas microcontroller. Table 6-13 details the
oscillators that are fitted and alternative footprints provided on this RSK:
Component
Crystal (X1) Fitted 12.5 MHz (HC49/4H package)
Table 6-13: 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 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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