MC9S08JM16 Datasheet, PDF (130/386 Pages) Freescale Semiconductor, Inc – Microcontrollers

Analog Comparator (S08ACMPV2)
Internal
Reference
ACBGS
ACME
Internal Bus
Status & Control
Register
ACIE
ACF
ACOPE
ACMP
INTERRUPT
REQUEST
ACMP+
ACMP–
+
-
Comparator
Interrupt
Control
ACMPO
Figure 9-2. Analog Comparator 5V (ACMP5) Block Diagram
9.2 External Signal Description
The ACMP has two analog input pins, ACMP+ and ACMP– and one digital output pin ACMPO. Each of
these 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 comparator non-inverting input if ACBGS is a 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 Memory Map
9.3.1 Register Descriptions
The ACMP includes one register:
MC9S08JM16 Series Data Sheet, Rev. 2
130
Freescale Semiconductor