HD64336900G Datasheet, PDF (94/408 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Tiny Series

5.1 Features
• Choice of two clock sources
Internal RC oscillator clock
External oscillator clock
• Choice of two types of RC oscillation frequency by the user software
8MHz ±5%
10MHz ±5%
• Frequency trimming
The initial frequency of the internal RC oscillator in the flash memory version is within the
range shown above, so users do not need to trim the frequency. As for the masked ROM
version (under planning), users can adjust the internal RC oscillation frequency to the range by
rewriting the trimming registers.
• Backup of the external oscillation halt
This system detects the external oscillation halt. If detected, the system clock source is
automatically switched to the internal RC oscillation clock.
• Interrupt can be requested to the CPU when the system clock is changed from the external
clock to the internal RC oscillator clock.
Rev. 1.00, 11/03, page 66 of 376