Microchip Technology MCU PIC PIC18F87K22-I/PTRSL TQFP-80 MCP PIC18F87K22-I/PTRSL Data Sheet
Product codes
PIC18F87K22-I/PTRSL
2009-2011 Microchip Technology Inc.
DS39960D-page 359
PIC18F87K22 FAMILY
The analog reference voltage is software-selectable to
either the device’s positive and negative supply voltage
(AV
either the device’s positive and negative supply voltage
(AV
DD
and AV
SS
) or the voltage level on the
RA3/AN3/V
REF
+ and RA2/AN2/V
REF
- pins. V
REF
+ has
two additional Internal Reference Voltage selections:
2.048V and 4.096V.
The A/D Converter can uniquely operate while the
device is in Sleep mode. To operate in Sleep, the A/D
conversion clock must be derived from the A/D
Converter’s internal RC oscillator.
The output of the Sample-and-Hold (S/H) is the input
into the converter, which generates the result via
successive approximation.
2.048V and 4.096V.
The A/D Converter can uniquely operate while the
device is in Sleep mode. To operate in Sleep, the A/D
conversion clock must be derived from the A/D
Converter’s internal RC oscillator.
The output of the Sample-and-Hold (S/H) is the input
into the converter, which generates the result via
successive approximation.
Each port pin associated with the A/D Converter can be
configured as an analog input or a digital I/O. The
ADRESH and ADRESL registers contain the result of
the A/D conversion. When the A/D conversion is com-
plete, the result is loaded into the ADRESH:ADRESL
register pair, the GO/DONE bit (ADCON0<1>) is
cleared and the A/D Interrupt Flag bit, ADIF (PIR1<6>),
is set.
A device Reset forces all registers to their Reset state.
This forces the A/D module to be turned off and any
conversion in progress is aborted. The value in the
ADRESH:ADRESL register pair is not modified for a
Power-on Reset. These registers will contain unknown
data after a Power-on Reset.
The block diagram of the A/D module is shown in
configured as an analog input or a digital I/O. The
ADRESH and ADRESL registers contain the result of
the A/D conversion. When the A/D conversion is com-
plete, the result is loaded into the ADRESH:ADRESL
register pair, the GO/DONE bit (ADCON0<1>) is
cleared and the A/D Interrupt Flag bit, ADIF (PIR1<6>),
is set.
A device Reset forces all registers to their Reset state.
This forces the A/D module to be turned off and any
conversion in progress is aborted. The value in the
ADRESH:ADRESL register pair is not modified for a
Power-on Reset. These registers will contain unknown
data after a Power-on Reset.
The block diagram of the A/D module is shown in
REGISTER 23-10: ANCON2: A/D PORT CONFIGURATION REGISTER 2
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
ANSEL23
)
ANSEL22
ANSEL21
ANSEL20
ANSEL19
ANSEL18
ANSEL17
ANSEL16
bit 7
bit 0
Legend:
R = Readable bit
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7-0
ANSEL<23:16>:
Analog Port Configuration bits (AN23 through AN16)
)
1
= Pin is configured as an analog channel; digital input is disabled and any inputs read as ‘0’
0
= Pin is configured as a digital port
Note 1:
AN15 through AN12 and AN23 through AN20 are implemented only on 80-pin devices. For 64-pin
devices, the corresponding ANSELx bits are still implemented for these channels, but have no effect.
devices, the corresponding ANSELx bits are still implemented for these channels, but have no effect.