Datasheet

PIC16C9XX
DS30444E - page 32  1997 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 Input/output or analog input
RA1/AN1
(1)
bit1 TTL Input/output or analog input
RA2/AN2
(1)
bit2 TTL Input/output or analog input
RA3/AN3/V
REF
(1)
bit3 TTL Input/output or analog input or VREF
RA4/T0CKI bit4 ST Input/output or external clock input for Timer0
Output is open drain type
RA5/AN4/SS
(1)
bit5 TTL Input/output or analog input or slave select input for synchronous serial port
Legend: TTL = TTL input, ST = Schmitt Trigger input
Note 1: The AN and V
REF functions are for the A/D module and are only implemented on the PIC16C924.
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Value on
Power-on
Reset
Value on
all other
resets
05h PORTA — — RA5 RA4 RA3 RA2 RA1 RA0 (2) (2)
85h TRISA — — PORTA Data Direction Control Register --11 1111 --11 1111
9Fh
(1)
ADCON1 — — — — — PCFG2 PCFG1 PCFG0 ---- -000 ---- -000
Legend: x = unknown, u = unchanged, - = unimplemented locations read as '0'. Shaded cells are not used by PORTA.
Note 1: The ADCON1 register is implemented on the PIC16C924 only.
2: PIC16C923 reset values for PORTA: --xx xxxx for a POR, and --uu uuuu for all other resets,
PIC16C924 reset values for PORTA: --0x 0000 when read.