MC9S08JM16 Datasheet, PDF (131/386 Pages) Freescale Semiconductor, Inc – Microcontrollers

Analog Comparator (S08ACMPV2)
• 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.
9.3.1.1 ACMP Status and Control Register (ACMPSC)
ACMPSC contains the status flag and control bits which are used to enable and configure the ACMP.
R
W
Reset:
7
ACME
0
6
ACBGS
5
ACF
4
ACIE
3
ACO
2
ACOPE
0
0
0
0
0
= Unimplemented
Figure 9-3. ACMP Status and Control Register
1
0
ACMOD
0
0
Table 9-2. ACMP Status and Control Register Field Descriptions
Field
7
ACME
6
ACBGS
5
ACF
4
ACIE
3
ACO
Description
Analog Comparator Module Enable — ACME enables the ACMP module.
0 ACMP not enabled
1 ACMP is enabled
Analog Comparator Bandgap Select — ACBGS is used to select between the bandgap reference voltage or
the ACMP+ pin as the input to the non-inverting input of the analog comparatorr.
0 External pin ACMP+ selected as non-inverting input to comparator
1 Internal reference select as non-inverting input to comparator
Note: refer to this chapter introduction to verify if any other config bits are necessary to enable the bandgap
reference in the chip level.
Analog Comparator Flag — ACF is set when a compare event occurs. Compare events are defined by ACMOD.
ACF is cleared by writing a one to ACF.
0 Compare event has not occurred
1 Compare event has occurred
Analog Comparator Interrupt Enable — ACIE enables the interrupt from the ACMP. When ACIE is set, an
interrupt will be asserted when ACF is set.
0 Interrupt disabled
1 Interrupt enabled
Analog Comparator Output — Reading ACO will return the current value of the analog comparator output. ACO
is reset to a 0 and will read as a 0 when the ACMP is disabled (ACME = 0).
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
131