MC9RS08KA8RM Datasheet, PDF (89/190 Pages) Freescale Semiconductor, Inc – MC9RS08KA8 Features

Analog Comparator (RS08ACMPV1)
Internal
Bandgap
Reference
Voltage
ACBGS
ACME
ACO
Internal Bus
Status and Control
Register
ACIE
ACF
ACOPE
ACMP
INTERRUPT
REQUEST
ACMP+
+
-
Interrupt
Control
ACME
ACMP–
Comparator
Figure 9-2. Analog Comparator (ACMP) Block Diagram
ACMPO
9.2 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 9-2, 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 9-2, the ACMPO pin can be enabled to drive an external pin.
The signal properties of ACMP are shown in Table 9-1.
Table 9-1. Signal Properties
Signal
Function
I/O
ACMP– Inverting analog input to the ACMP
I
(Minus input)
ACMP+ Non-inverting analog input to the ACMP
I
(Positive input)
ACMPO Digital output of the ACMP
O
9.3 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.
MC9RS08KA8 Series Reference Manual, Rev. 3
Freescale Semiconductor
89