Microchip Technology DM164134 Data Sheet
PIC18FXX8
DS41159E-page 94
© 2006 Microchip Technology Inc.
FIGURE 9-1:
RA3:RA0 AND RA5 PINS
BLOCK DIAGRAM
BLOCK DIAGRAM
FIGURE 9-2:
RA4/T0CKI PIN BLOCK
DIAGRAM
DIAGRAM
FIGURE 9-3:
OSC2/CLKO/RA6 PIN BLOCK DIAGRAM
Data Bus
P
N
WR LATA
WR TRISA
Data Latch
TRIS Latch
RD TRISA
RD PORTA
V
SS
V
DD
I/O pin
(1)
Note 1:
I/O pins have diode protection to V
DD
and V
SS
.
Analog
Input Mode
Input Mode
TTL
Input
Buffer
Input
Buffer
To A/D Converter and LVD Modules
RD LATA
or
WR PORTA
SS Input (RA5 only)
Q
D
Q
CK
Q
D
Q
CK
Q
D
EN
Data Bus
WR TRISA
RD PORTA
Data Latch
TRIS Latch
RD TRISA
Schmitt
Trigger
Input
Buffer
Trigger
Input
Buffer
N
V
SS
I/O pin
(1)
TMR0 Clock Input
Note 1: I/O pin has diode protection to V
SS
only.
Q
D
Q
CK
Q
D
Q
CK
Q
D
EN
RD LATA
WR LATA or
WR PORTA
WR PORTA
TTL
Input
Buffer
Input
Buffer
Data Bus
P
N
WR PORTA
WR TRISA
Data Latch
TRIS Latch
RD TRISA
RD PORTA
V
SS
V
DD
Oscillator
Circuit
From OSC1
1
0
(F
OSC
= 101, 111)
Data Latch
CLKO (F
OSC
/4)
OSC2/CLKO
RA6 pin
(2)
(F
OSC
= 100,
Schmitt
Trigger
Input Buffer
Trigger
Input Buffer
(F
OSC
= 110, 100)
Q
D
Q
CK
Q
D
Q
CK
Q
D
EN
101
, 110, 111)
Note
1: CLKO is 1/4 of F
OSC
.
2: I/O pin has diode protection to V
DD
and V
SS
.