
2005 Microchip Technology Inc.
DS39612B-page 107
PIC18F6525/6621/8525/8621
FIGURE 10-6:
BLOCK DIAGRAM OF RB2:RB0 PINS
FIGURE 10-7:
BLOCK DIAGRAM OF RB3 PIN
Data Latch
RBPU(2)
P
VDD
Q
D
CK
Q
D
CK
QD
EN
Data Bus
WR TRISB
RD TRISB
RD PORTB
Weak
Pull-up
RD Port
INTx
I/O pin(1)
TTL
Input
Buffer
Schmitt Trigger
Buffer
TRIS Latch
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 (INTCON2<7>).
WR LATB or
WR PORTB
Data Latch
P
VDD
Q
D
CK
Q
D
EN
Data Bus
WR LATB or
WR TRISB
RD TRISB
RD PORTB
Weak
Pull-up
ECCP2 or INT3
TTL
Input
Buffer
Schmitt Trigger
Buffer
TRIS Latch
RD LATB
WR PORTB
RBPU(2)
CK
D
Enable(3)
ECCP Output
RD PORTB
ECCP Output(3)
1
0
P
N
VDD
VSS
I/O pin(1)
Q
CCP2MX
CCP2MX = 0
Note
1:
I/O pin has diode protection to VDD and VSS.
2:
To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit (INTCON2<7>).
3:
For PIC18F8525/8621 parts, the ECCP2 input/output is multiplexed with RB3 if the CCP2MX bit is enabled (= 0)
in the Configuration register and the device is operating in Microprocessor, Microprocessor with Boot Block or
Extended Microcontroller mode.