R8C33A Datasheet, PDF (151/617 Pages) Renesas Technology Corp – MCU M16C FAMILY / R8C/Tiny SERIES

Under development ^{Preliminary specification}
Specifications in this manual are tentative and subject to change.
R8C/33A Group
9. Clock Generation Circuit
9.8 Oscillation Stop Detection Function
The oscillation stop detection function detects the stop of the XIN clock oscillating circuit.
The oscillation stop detection function can be enabled and disabled by the OCD0 bit in the OCD register.
Table 9.5 lists the Specifications of Oscillation Stop Detection Function.
When the XIN clock is the CPU clock source and bits OCD1 to OCD0 are set to 11b, the MCU is placed in the
following state if the XIN clock stops.
• OCD2 bit in OCD register = 1 (on-chip oscillator clock selected)
• OCD3 bit in OCD register = 1 (XIN clock stops)
• CM14 bit in CM1 register = 0 (low-speed on-chip oscillator oscillates)
• Oscillation stop detection interrupt request is generated
Table 9.5 Specifications of Oscillation Stop Detection Function
Item
Oscillation stop detection clock and
frequency bandwidth
Enabled condition for oscillation stop
detection function
Operation at oscillation stop detection
f(XIN) ≥ 2 MHz
Specification
Bits OCD1 to OCD0 set to 11b
Oscillation stop detection interrupt generated
REJ09B0455-0010 Rev.0.10 Feb 29, 2008
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