C8051F960-B-GM Datasheet, PDF (108/492 Pages) Silicon Laboratories – Ultra Low Power 128K, LCD MCU Family

C8051F96x
7.5. Comparator Register Descriptions
The SFRs used to enable and configure the comparators are described in the following register descrip-
tions. A Comparator must be enabled by setting the CPnEN bit to logic 1 before it can be used. From an
enabled state, a comparator can be disabled and placed in a low power state by clearing the CPnEN bit to
logic 0.
Important Note About Comparator Settings: False rising and falling edges can be detected by the Com-
parator while powering on or if changes are made to the hysteresis or response time control bits. There-
fore, it is recommended that the rising-edge and falling-edge flags be explicitly cleared to logic 0 a short
time after the comparator is enabled or its mode bits have been changed. The Comparator Power Up Time
is specified in Section “Table 4.16. Comparator Electrical Characteristics” on page 74.
SFR Definition 7.1. CPT0CN: Comparator 0 Control
Bit
7
6
5
4
3
2
1
0
Name
Type
Reset
CP0EN
R/W
0
CP0OUT
R
0
CP0RIF
R/W
0
CP0FIF
R/W
0
CP0HYP[1:0]
R/W
0
0
CP0HYN[1:0]
R/W
0
0
SFR Page= 0x0; SFR Address = 0x9B
Bit
Name
Function
7
CP0EN _{Comparator0 Enable Bit.}
0: Comparator0 Disabled.
1: Comparator0 Enabled.
6
CP0OUT _{Comparator0 Output State Flag.}
0: Voltage on CP0+ < CP0–.
1: Voltage on CP0+ > CP0–.
5
CP0RIF _{Comparator0 Rising-Edge Flag. Must be cleared by software.}
0: No Comparator0 Rising Edge has occurred since this flag was last cleared.
1: Comparator0 Rising Edge has occurred.
4
CP0FIF _{Comparator0 Falling-Edge Flag. Must be cleared by software.}
0: No Comparator0 Falling-Edge has occurred since this flag was last cleared.
1: Comparator0 Falling-Edge has occurred.
3-2 CP0HYP[1:0] _{Comparator0 Positive Hysteresis Control Bits.}
00: Positive Hysteresis Disabled.
01: Positive Hysteresis = 5 mV.
10: Positive Hysteresis = 10 mV.
11: Positive Hysteresis = 20 mV.
1-0 CP0HYN[1:0] _{Comparator0 Negative Hysteresis Control Bits.}
00: Negative Hysteresis Disabled.
01: Negative Hysteresis = 5 mV.
10: Negative Hysteresis = 10 mV.
11: Negative Hysteresis = 20 mV.
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