Datasheet

PIC16F87X
DS30292C-page 30  2001 Microchip Technology Inc.
TABLE 3-1: PORTA FUNCTIONS
TABLE 3-2: SUMMARY OF REGISTERS ASSOCIATED WITH PORTA
Name Bit# Buffer Function
RA0/AN0 bit0 TTL Input/output or analog input.
RA1/AN1 bit1 TTL Input/output or analog input.
RA2/AN2 bit2 TTL Input/output or analog input.
RA3/AN3/V
REF 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/SS
/AN4 bit5 TTL Input/output or slave select input for synchronous serial port or analog input.
Legend: TTL = TTL input, 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,
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 --11 1111
9Fh ADCON1 ADFM — — — PCFG3 PCFG2 PCFG1 PCFG0
--0- 0000 --0- 0000
Legend: x = unknown, u = unchanged, - = unimplemented locations read as '0'.
Shaded cells are not used by PORTA.
Note: When using the SSP module in SPI Slave mode and SS enabled, the A/D converter must be set to one of
the following modes, where PCFG3:PCFG0 = 0100,0101, 011x, 1101, 1110, 1111.