HD64F2168 Datasheet, PDF (766/874 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer

22.8.3 Note on Operation Check
This LSI may oscillate at several kHz of frequency even when a crystal resonator is not connected
to the EXTAL and XTAL pins or an external clock is not input. Use this LSI after confirming that
the LSI operates with appropriate frequency.
Rev. 3.00, 03/04, page 726 of 830