MC9S08RC8 Datasheet, PDF (182/234 Pages) Freescale Semiconductor, Inc – Microcontrollers

Analog Comparator (ACMP) Block Description
14.5 ACMP Status and Control Register (ACMP1SC)
R
W
Reset
7
ACME
6
ACBGS
5
ACF
4
ACIE
3
ACO
2
1
0
ACMOD1
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 14-3. ACMP Status and Control Register (ACMP1SC)
0
ACMOD0
0
Table 14-1. ACMP1SC Field Descriptions
Field
Description
7
ACME
Analog Comparator Module Enable — The ACME bit enables the analog comparator module. When the
module is not enabled, it remains in a low-power state.
0 Analog comparator disabled
1 Analog comparator enabled
6
ACBGS
Analog Comparator Bandgap Select — The ACBGS bit is used to select the internal bandgap as the
comparator reference.
0 External pin ACMP1+ selected as comparator non-inverting input
1 Internal bandgap reference selected as comparator non-inverting input
5
Analog Comparator Flag — The ACF bit is set when a compare event occurs. Compare events are defined by
ACF the ACMOD0 and ACMOD1 bits. The ACF bit is cleared by writing a 1 to the bit.
0 Compare event has not occurred.
1 Compare event has occurred.
4
ACIE
Analog Comparator Interrupt Enable — The ACIE bit enables the interrupt from the ACMP. When this bit is
set, an interrupt will be asserted when the ACF bit is set.
0 Interrupt disabled
1 Interrupt enabled
3
ACO
Analog Comparator Output — Reading the ACO bit will return the current value of the analog comparator
output. The register bit is reset to 0 and will read as 0 when the analog comparator module is disabled (ACME =
0).
1:0
Analog Comparator Modes — The ACMOD1 and ACMOD0 bits select the flag setting mode that controls the
ACMOD[1:0] type of compare event that sets the ACF bit.
00 Comparator output falling edge
01 Comparator output rising edge
10 Comparator output falling edge
11 Comparator output either rising or falling edge
MC9S08RC/RD/RE/RG Data Sheet, Rev. 1.11
182
Freescale Semiconductor