NXP Semiconductors MC9S08QL4, Reference Manual

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Analog Comparator (S08ACMPVLPV1)
MC9S08QL8 MCU Series Reference Manual, Rev. 1
116 NXP Semiconductors
9.1.5 Features
The ACMP has the following features:
• Full rail-to-rail supply operation
• Low input offset and hysteresis
• Selectable interrupt on rising edge, falling edge, or rising and falling edges of comparator output
• Option to compare to fixed internal bandgap reference voltage
9.1.6 Modes of Operation
9.1.6.1 Wait Mode Operation
During wait mode the ACMP, if enabled, continues to operate normally. Also, if enabled, the interrupt can
wake the MCU.
9.1.6.2 Stop3 Mode Operation
If enabled, the ACMP continues to operate in stop3 mode and compare operation remains active. If
ACOPE is enabled, comparator output operates in the normal operating mode and comparator output is
placed onto the external pin. The MCU is brought out of stop when a compare event occurs and ACIE is
enabled; ACF flag sets accordingly.
If stop is exited with a reset, the ACMP will be put into its reset state.
9.1.6.3 Stop2 Mode Operation
During stop2 mode, the ACMP module is fully powered down. Upon wakeup from stop2 mode, the ACMP
module is in the reset state.
9.1.6.4 Active Background Mode Operation
When the microcontroller is in active background mode, the ACMP continues to operate normally. When
ACMPO is shared with the BKGD pin and the BKGD pin is enabled, the ACMPO function is not
available.
9.1.7 Block Diagram
The block diagram for the ACMP module follows.