ST7LITE1XB Datasheet, PDF (103/157 Pages) STMicroelectronics – 8-BIT MCU WITH SINGLE VOLTAGE FLASH MEMORY, DATA EEPROM, ADC, 5 TIMERS, SPI

ST7LITE1xB
ANALOG COMPARATOR (Cont’d)
Bit 4 = CMPIF Comparator Interrupt Flag
This bit is set by hardware when interrupt is gener-
ated at the rising edge (CINV = 0) or falling edge
(CINV = 1) of comparator output. This bit is
cleared by reading the CMPCR register. Writing to
this bit does not change the value.
0 : Comparator interrupt flag cleared
1 : Comparator interrupt flag set and can generate
interrupt if CMPIE is set.
Bit 3 : CMPIE Comparator Interrupt Enable
This bit is set or reset by software and cleared by
hardware reset. This bit enables or disables the in-
terrupt generation depending on interrupt flag
0: Interrupt not generated
1: Interrupt generated if interrupt flag is set
Note:
This bit should be set to enable interrupt only after
the comparator has been switched ON, i.e. when
CMPON is set.
Once CMPON bit is set, it is recommended to wait
the specified stabilization time before setting
CMPIE bit in order to avoid a spurious interrupt
(see section 13.12 on page 142).
Bit 1 = COUT Comparator Output Enable on Port
This bit is set or cleared by software. When this bit
is set, the comparator output is available on PA7
port.
0 : Comparator output not connected to PA7
1 : Comparator output connected to PA7
Bit 0 : CMPON Comparator ON/OFF
This bit is set or cleared by software and reset by
hardware reset. This bit is used to switch ON/OFF
the comparator, internal voltage reference and
current bias which provides 4µA current to both.
0: Comparator, Internal Voltage Reference, Bias
OFF (in power-down state).
1: Comparator, Internal Voltage Reference, Bias
ON
Note: For the comparator interrupt generation, it
takes 250ns delay from comparator output change
to rising or falling edge of interrupt generated.
Bit 2 : CMP Comparator Output
This bit is set or reset by software and cleared by
hardware reset. It stores the value of comparator
output.
Table 21. Analog Comparator Register Map and Reset Values
Address
(Hex.)
Register
Label
002Ch
002Dh
VREFCR
Reset Value
CMPCR
Reset value
7
6
5
VCEXT
0
CHYST
1
VCBGR
0
-
0
VR3
0
CINV
0
4
3
VR2
0
CMPIF
0
VR1
0
CMPIE
0
2
VR0
0
CMP
0
1
0
-
0
COUT
0
-
0
CMPON
0
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