PIC16F87-E Datasheet, PDF (55/228 Pages) Microchip Technology – 18/20/28-Pin Enhan lashMicrocontrollers with nanoWatt Technology

PIC16F87/88
FIGURE 5-2:
BLOCK DIAGRAM OF RA3/AN3/VREF+/C1OUT PIN
Data
Bus
WR
PORTA
WR
TRISA
D
Q
CK Q
Data Latch
D
Q
CK Q
TRIS Latch
Comparator Mode = 110
Comparator 1 Output
Analog
Input Mode
RD TRISA
VDD
P
N
VSS
TTL
Input Buffer
Q
D
EN
RD PORTA
To Comparator
To A/D Module Channel Input (PIC16F88 only)
To A/D Module Channel VREF+ Input (PIC16F88 only)
VDD
RA3 pin
VSS
FIGURE 5-3:
BLOCK DIAGRAM OF RA2/AN2/CVREF/VREF- PIN
Data
Bus
WR
PORTA
D
Q
CK Q
Data Latch
D
Q
WR
TRISA
CK Q
TRIS Latch
RD TRISA
RD PORTA
To Comparator
To A/D Module VREF- (PIC16F88 only)
To A/D Module Channel Input (PIC16F88 only)
CVROE
CVREF
Q
D
EN
VDD
P
VDD
N
VSS _Analog
Input Mode
RA2 pin
TTL
Input Buffer
 2005 Microchip Technology Inc.
DS30487C-page 53