NXP Semiconductors MC9S08QL4, Reference Manual

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Analog Comparator (S08ACMPVLPV1)
MC9S08QL8 MCU Series Reference Manual, Rev. 1
NXP Semiconductors 117
Figure 9-1. Analog Comparator Module Block Diagram
9.2 External Signal Description
The ACMP has two analog input pins: ACMP- and ACMP+. Each of these pins can accept an input voltage
that varies across the full operating voltage range of the MCU. If the module is not enabled, each of these
pins can be used as digital inputs or outputs. Consult the specific MCU documentation to determine what
functions are shared with these analog inputs. As shown in the block diagram, the ACMP+ pin is
connected to the comparator non-inverting input if ACBGS is equal to logic zero, and the ACMP- pin is
connected to the inverting input of the comparator.
9.3 Register Definition
9.3.1 Status and Control Register (ACMPxSC)
7 6 5 4 3 2 1 0
R
ACME ACBGS ACF ACIE
ACO
ACOPE ACMOD1 ACMOD0
W
Reset: 0 0 0 0 0 0 0 0
= Unimplemented
Figure 9-2. ACMP Status and Control Register (ACMPxSC)
+
–
ACMPx+
ACMPx-
Interrupt
Control
AC IRQ
Internal
Reference
ACBGS
Internal Bus
Status & Control
Register
ACMOD1
ACMOD2
SET
A
CF
ACPE
ACF
ACIE
ACOPE
ACO
ACMPxO