PIC18FXX20
TABLE 10-1: PORTA FUNCTIONS
Name
RA0/AN0
RA1/AN1
RA2/AN2/VREF-
RA3/AN3/VREF+
RA4/T0CKI
Bit#
Buffer
Function
bit0
bit1
bit2
bit3
bit4
TTL
TTL
TTL
TTL
ST
Input/output or analog input.
Input/output or analog input.
Input/output or analog input or VREF-.
Input/output or analog input or VREF+.
Input/output or external clock input for Timer0.
Output is open drain type.
RA5/AN4/LVDIN
OSC2/CLKO/RA6
bit5
bit6
TTL
TTL
Input/output or slave select input for synchronous serial port or analog
input, or low voltage detect input.
OSC2 or clock output, or I/O pin.
Legend: TTL = TTL input, ST = Schmitt Trigger input
TABLE 10-2: SUMMARY OF REGISTERS ASSOCIATED WITH PORTA
Value on
all other
RESETS
Value on
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
POR, BOR
PORTA
LATA
TRISA
ADCON1
—
—
—
—
RA6
RA5
RA4
RA3
RA2
RA1
RA0
-x0x 0000 -u0u 0000
-xxx xxxx -uuu uuuu
-111 1111 -111 1111
LATA Data Output Register
PORTA Data Direction Register
—
VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 --00 0000 --00 0000
Legend: x= unknown, u= unchanged, - = unimplemented locations read as '0'.
Shaded cells are not used by PORTA.
2003 Microchip Technology Inc.
Advance Information
DS39609A-page 105