Datasheet

ACMP_C1 field descriptions
Field Description
7
DACEN
DAC Enable
The DACEN bit enables the output of 6-bit DAC.
0 The DAC is disabled.
1 The DAC is enabled.
6
DACREF
DAC Reference Select
0 The DAC selects Bandgap as the reference.
1 The DAC selects V
DDA
as the reference.
5–0
DACVAL
DAC Output Level Selection
Select the output voltage using the given formula: V
output
= (V
in
/64)x(DACVAL[5:0]+1) The V
output
range is
from V
in
/64 to V
in
, the step is V
in
/64
20.3.4 ACMP Control Register 2 (ACMP_C2)
Address: 2Ch base + 3h offset = 2Fh
Bit 7 6 5 4 3 2 1 0
Read 0
ACIPE
Write
Reset
0 0 0 0 0 0 0 0
ACMP_C2 field descriptions
Field Description
7–3
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
2–0
ACIPE
ACMP Input Pin Enable
This 3-bit register controls if the corresponding ACMP external pin can be driven an analog input.
0 The corresponding external analog input is not allowed.
1 The corresponding external analog input is allowed.
20.4 Functional description
The ACMP module is functionally composed of two parts: digital-to-analog (DAC) and
comparator (CMP).
The DAC includes a 64-level DAC (digital to analog convertor) and relevant control
logic. DAC can select one of two reference inputs, V
DD
or on-chip bandgap, as the DAC
input V
in
by setting ACMP_C1[DACREF] bit. After the DAC is enabled, it converts the
Functional description
MC9S08PA60 Reference Manual, Rev. 1, 9/2012
562 Freescale Semiconductor, Inc.