
PIC16C63A/65B/73B/74B
DS30605C-page 30
2000 Microchip Technology Inc.
TABLE 5-1:
PORTA FUNCTIONS
TABLE 5-2:
SUMMARY OF REGISTERS ASSOCIATED WITH PORTA
Name
Bit#
Buffer
Function
RA0/AN0(1)
bit0
TTL
Digital input/output or analog input.
RA1/AN1(1)
bit1
TTL
Digital input/output or analog input.
RA2/AN2(1)
bit2
TTL
Digital input/output or analog input.
RA3/AN3/VREF(1)
bit3
TTL
Digital input/output or analog input or VREF.
RA4/T0CKI
bit4
ST
Digital input/output or external clock input for Timer0.
Output is open drain type.
RA5/SS/AN4(1)
bit5
TTL
Input/output or slave select input for synchronous serial port or analog input.
Legend: TTL = TTL input, ST = Schmitt Trigger input
Note 1: The A/D is not implemented on the PIC16C63A/65B. Pins will operate as digital I/O only. ADCON1 is not
implemented; maintain this register clear.
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on:
POR,
BOR
Value on
all other
RESETS
05h
PORTA
—
RA5
RA4
RA3
RA2
RA1
RA0
--0x 0000
--0u 0000
85h
TRISA
—
PORTA Data Direction Register
--11 1111
9Fh
ADCON1
(1)
—
PCFG2
PCFG1
PCFG0
---- -000
Legend: x = unknown, u = unchanged, - = unimplemented locations read as '0'. Shaded cells are not used by PORTA.
Note
1: The A/D is not implemented on the PIC16C63A/65B. Pins will operate as digital I/O only. ADCON1 is not implemented;
maintain this register clear.