M16C65 Datasheet, PDF (143/829 Pages) Renesas Technology Corp – RENESAS MCU M16C FAMILY / M16C/60

Under development
M16C/65 Group
Preliminary Specification
This is a preliminary specification and is subject to change.
8. Clock Generator
CM22 (Oscillation Stop and Re-Oscillation Detection Flag) (b2)
Condition to become 0:
• Set it to 0.
Condition to become 1:
• Main clock stop is detected.
• Main clock re-oscillation is detected.
(The CM22 bit remains unchanged even if 1 is written.)
When the CM22 bit changes state from 0 to 1, an oscillation stop/re-oscillation detection interrupt is
generated. Use this bit in an interrupt routine to determine the factors of interrupts between the
oscillation stop and re-oscillation detection interrupt and the watchdog timer interrupt.
When the CM22 bit is 1 and oscillation stop or re-oscillation is detected, an oscillation stop/re-oscillation
detection interrupt is not generated. The bit is not set to 0 even if an oscillation stop/re-oscillation
detection interrupt request is accepted.
CM23 (XIN Monitor Flag) (b3)
Determine the main clock status by reading the CM23 bit several times in the oscillation stop and re-
oscillation detection interrupt routine.
REJ09B0484-0030 Rev.0.30 Sep 09, 2008
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