mc9s08en32 Freescale Semiconductor, Inc, mc9s08en32 Datasheet - Page 160

• Manufacturer Part Number: mc9s08en32
• Description: Hcs08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Chapter 9 Analog Comparator (S08ACMPV3)
9.4
The analog comparator can compare two analog input voltages applied to ACMP1+ and ACMP1−, or it
can compare an analog input voltage applied to ACMP1− with an internal bandgap reference voltage.
ACBGS selects between the bandgap reference voltage or the ACMP1+ pin as the input to the
non-inverting input of the analog comparator. The comparator output is high when the non-inverting input
is greater than the inverting input, and is low when the non-inverting input is less than the inverting input.
ACMOD selects the condition that causes ACF to be set. ACF can be set on a rising edge of the comparator
output, a falling edge of the comparator output, or a rising or a falling edge (toggle). The comparator output
can be read directly through ACO. The comparator output can be driven onto the ACMP1O pin using
ACOPE.
160
ACMOD
ACOPE
Field
ACO
1:0
3
2
Functional Description
Analog Comparator Output. Reading ACO returns the current value of the analog comparator output. ACO is
reset to a 0 and reads as a 0 when the ACMP is disabled (ACME = 0).
Analog Comparator Output Pin Enable. Enables the comparator output to be placed onto the external pin,
ACMP1O.
0 Analog comparator output not available on ACMP1O
1 Analog comparator output is driven out on ACMP1O
Analog Comparator Mode. ACMOD selects the type of compare event which sets ACF.
00 Encoding 0 — Comparator output falling edge
01 Encoding 1 — Comparator output rising edge
10 Encoding 2 — Comparator output falling edge
11 Encoding 3 — Comparator output rising or falling edge
Table 9-3. ACMP1SC Field Descriptions (continued)
MC9S08EN32 Series Data Sheet, Rev. 3
Description
Freescale Semiconductor