MC9S08EL32 Datasheet, PDF (133/356 Pages) Freescale Semiconductor, Inc – 8-Bit HCS08 Central Processor Unit (CPU)

Analog Comparator (S08ACMPV2)
9.2 External Signal Description
The ACMP has two analog input pins, ACMPx+ and ACMPx- and one digital output pin ACMPxO. 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 ACMPx- pin is connected to the inverting input of the comparator, and the
ACMPx+ pin is connected to the comparator non-inverting input if ACBGS is a 0. As shown in Figure 9-2,
the ACMPxO pin can be enabled to drive an external pin.
The signal properties of ACMP are shown in Table 9-2.
Table 9-2. Signal Properties
Signal
Function
I/O
ACMPx- Inverting analog input to the ACMP.
I
(Minus input)
ACMPx+ Non-inverting analog input to the ACMP.
I
(Positive input)
ACMPxO Digital output of the ACMP.
O
9.3 Memory Map
9.3.1 Register Descriptions
The ACMP includes one register:
• An 8-bit status and control register
Refer to the direct-page register summary in the memory section of this data sheet for the absolute address
assignments for all ACMP registers.This section refers to registers and control bits only by their names .
Some MCUs may have more than one ACMP, so register names include placeholder characters to identify
which ACMP is being referenced.
MC9S08EL32 Series and MC9S08SL16 Series Data Sheet, Rev. 3
Freescale Semiconductor
133