Renesas H8SX/1668R - Manual (Page 20)

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.
6.9. USB port
This RSK has a Full-speed (12 Mbps) USB port compliant to USB 2.0 specification. It is available as J12 on the RSK. This port allows Boot
mode programming using USB Direct connection. For more details please refer to H8SX/1668R Group Hardware Manual.
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