
PIC16C55X
DS40143D-page 24
Preliminary
2002 Microchip Technology Inc.
TABLE 5-1:
PORTA FUNCTIONS
TABLE 5-2:
SUMMARY OF REGISTERS ASSOCIATED WITH PORTA
Name
Bit #
Buffer
Type
Function
RA0
Bit 0
ST
Bi-directional I/O port.
RA1
Bit 1
ST
Bi-directional I/O port.
RA2
Bit 2
ST
Bi-directional I/O port.
RA3
Bit 3
ST
Bi-directional I/O port.
RA4/T0CKI
Bit 4
ST
Bi-directional I/O port or external clock input for TMR0. Output is open
drain type.
Legend: ST = Schmitt Trigger input
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR
Value on
All Other
RESETS
05h
PORTA
—
RA4
RA3
RA2
RA1
RA0
---x xxxx
---u uuuu
85h
TRISA
—
TRISA4 TRISA3 TRISA2 TRISA1 TRISA0
---1 1111
Legend:
— = Unimplemented locations, read as ‘0’, x = unknown, u = unchanged
Note
1: Shaded bits are not used by PORTA.