Datasheet

 2010 Microchip Technology Inc. DS41326E-page 29
PIC16F526
6.4 I/O Interfacing
The equivalent circuit for an I/O port pin is shown in
Figure 6-1. All port pins, except RB3 which is input-
only, may be used for both input and output operations.
For input operations, these ports are non-latching. Any
input must be present until read by an input instruction
(e.g., MOVF PORTB, W). The outputs are latched and
remain unchanged until the output latch is rewritten. To
use a port pin as output, the corresponding direction
control bit in TRIS must be cleared (= 0). For use as an
input, the corresponding TRIS bit must be set. Any I/O
pin (except RB3) can be programmed individually as
input or output.
FIGURE 6-1: BLOCK DIAGRAM OF RB0
AND RB1 (with Weak Pull-
up and Wake-up on
Change)
Data
Bus
QD
Q
CK
QD
Q
CK
WR
Port
TRIS ‘f’
Data
TRIS
RD Port
W
Reg
Latch
Latch
Reset
Note 1: I/O pins have protection diodes to VDD and
V
SS.
2: Pin enabled as analog for ADC or comparator.
D
CK
Q
Pin Change
RBPU
ADC pin Ebl
COMP pin Ebl
ADC
COMP
I/O Pin
(1)
(2)
(2)