
PIC16F913/914/916/917/946
DS41250F-page 48
2007 Microchip Technology Inc.
3.2.1.4
RA3/AN3/C1+/VREF+/COM3/SEG15
Figure 3-4 shows the diagram for this pin. The RA3 pin
is configurable to function as one of the following:
a general purpose input
an analog input for the ADC
an analog input from Comparator C1
a voltage reference input for the ADC
analog outputs for the LCD
FIGURE 3-4:
BLOCK DIAGRAM OF RA3
Q
D
Q
CK
Data Latch
TRIS Latch
RD TRISA
RD PORTA
Q
D
Q
CK
TTL
Input Buffer
To A/D Converter and Comparator
COM3(1) or SEG15
Data Bus
WR PORTA
WR TRISA
To A/D Module VREF+ Input
Note 1:
PIC16F913/916 only.
2:
For the PIC16F913/916, the LCDMODE_EN = LCDEN and (SE15 or LMUX<1:0> = 11).
For the PIC16F914/917 and PIC16F946, the LCDMODE_EN = LCDEN and SE15.
Q
LCDMODE_EN(2)
Analog Input or
I/O Pin
LCDMODE_EN(2)
VDD
VSS