PIC16F877-20L Datasheet, PDF (30/218 Pages) Microchip Technology – 28/40-Pin 8-Bit CMOS FLASH Microcontrollers

PIC16F87X
TABLE 3-1: PORTA FUNCTIONS
Name
Bit# Buffer
Function
RA0/AN0
RA1/AN1
bit0 TTL Input/output or analog input.
bit1 TTL Input/output or analog input.
RA2/AN2
bit2 TTL Input/output or analog input.
RA3/AN3/VREF
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
TABLE 3-2: SUMMARY OF REGISTERS ASSOCIATED WITH PORTA
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3
Bit 2
Bit 1
Bit 0
Value on: Value on all
POR,
other
BOR
RESETS
05h PORTA
—
— RA5 RA4 RA3 RA2 RA1 RA0 --0x 0000
85h TRISA
— — PORTA Data Direction Register
--11 1111
9Fh ADCON1 ADFM — — — PCFG3 PCFG2 PCFG1 PCFG0 --0- 0000
Legend: x = unknown, u = unchanged, - = unimplemented locations read as '0'.
Shaded cells are not used by PORTA.
--0u 0000
--11 1111
--0- 0000
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.
DS30292D-page 30
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