PIC16F87-E Datasheet, PDF (64/228 Pages) Microchip Technology – 18/20/28-Pin Enhan lashMicrocontrollers with nanoWatt Technology

PIC16F87/88
FIGURE 5-11:
BLOCK DIAGRAM OF RB3/PGM/CCP1⁽³⁾ PIN
CCP1M<3:0> = 1000, 1001, 11xx and CCPMX = 0
CCP
CCP1M<3:0> = 0100, 0101, 0110, 0111 and CCPMX = 0
0
or LVP = 1
1
RBPU⁽²⁾
Data Bus
WR
PORTB
WR
TRISB
Data Latch
DQ
CK
TRIS Latch
DQ
CK
RD TRISB
VDD
P
Weak
Pull-up
I/O pin⁽¹⁾
TTL
Input
Buffer
RD PORTB
Q
D
EN
To PGM or CCP
RD PORTB
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: The CCP1 pin is determined by the CCPMX bit in Configuration Word 1 register.
DS30487C-page 62
 2005 Microchip Technology Inc.