PIC16F87_05 Datasheet, PDF (68/228 Pages) Microchip Technology – 18/20/28-Pin Enhanced Flash Microcontrollers with nanoWatt Technology

PIC16F87/88
FIGURE 5-15:
BLOCK DIAGRAM OF RB7/AN6⁽³⁾/PGD/T1OSI PIN
Port/Program Mode/ICD
PGD
1
Analog Input Mode
0
RBPU⁽²⁾
Data Bus
WR
PORTB
WR
TRISB
Data Latch
DQ
CK
TRIS Latch
DQ
CK
VDD
P
Weak
Pull-up
I/O pin⁽¹⁾
0
1
T1OSCEN
PGD DRVEN
RD TRISB
Set RBIF
RD PORTB
T1OSCEN
Analog
Input Mode
TTL
Input Buffer
Latch
QD
EN
Q1
From other
RB7:RB4 pins
QD
RD PORTB
EN
Q3
PGD
To T1OSCI Input
To A/D Module Channel Input (PIC16F88 only)
Note 1: I/O pins have diode protection to VDD and VSS.
2: To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit.
3: PIC16F88 devices only.
DS30487C-page 66
 2005 Microchip Technology Inc.