Datasheet

Analog Comparator (RS08ACMPV1)
MC9RS08KA2 Series Data Sheet, Rev. 4
86 Freescale Semiconductor
10.2 External Signal Description
The ACMP has two analog input pins, ACMP+ and ACMP–, and one digital output pin, ACMPO. Each
of the input pins can accept an input voltage that varies across the full operating voltage range of the MCU.
As shown in Figure 10-2, the ACMP– pin is connected to the inverting input of the comparator, and the
ACMP+ pin is connected to the non-inverting input of the comparator if ACBGS=0. As shown in
Figure 10-2, the ACMPO pin can be enabled to drive an external pin.
The signal properties of ACMP are shown in Table 10-1.
10.3 Register Definition
The ACMP includes one register:
• An 8-bit status and control register
Refer to the direct-page register summary in the memory chapter of this data sheet for the absolute address
assignments for all ACMP registers.
10.3.1 ACMP Status and Control Register (ACMPSC)
ACMPSC contains the status flag and control bits which are used to enable and configure the ACMP.
Table 10-1. Signal Properties
Signal Function I/O
ACMP- Inverting analog input to the ACMP
(Minus input)
I
ACMP+ Non-inverting analog input to the ACMP
(Positive input)
I
ACMPO Digital output of the ACMP O
76543210
R
ACME ACBGS ACF ACIE
ACO
ACOPE ACMOD
W
Reset:00000000
= Unimplemented
Figure 10-3. ACMP Status and Control Register (ACMPSC)