PIC16F87X
TABLE 3-1:
Name
PORTA FUNCTIONS
Bit#
Buffer
Function
RA0/AN0
bit0
bit1
bit2
bit3
bit4
TTL
TTL
TTL
TTL
ST
Input/output or analog input
Input/output or analog input
Input/output or analog input
RA1/AN1
RA2/AN2
RA3/AN3/VREF
RA4/T0CKI
Input/output or analog input or VREF
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
Value on: Value on all
Address Name
Bit 7 Bit 6 Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
POR,
BOR
other
resets
--0x 0000 --0u 0000
--11 1111 --11 1111
--0- 0000 --0- 0000
05h
85h
9Fh
PORTA
—
—
—
—
—
RA5
RA4
RA3
RA2
RA1
RA0
TRISA
PORTA Data Direction Register
PCFG3 PCFG2 PCFG1 PCFG0
ADCON1 ADFM
—
—
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.
DS30292B-page 30
1999 Microchip Technology Inc.
ETC [ ETC ]
