2004 Microchip Technology Inc.
DS30498C-page 55
PIC16F7X7
TABLE 5-1:
PORTA FUNCTIONS
TABLE 5-2:
SUMMARY OF REGISTERS ASSOCIATED WITH PORTA
Name
Bit#
Buffer
Function
RA0/AN0
bit 0
TTL
Input/output or analog input.
RA1/AN1
bit 1
TTL
Input/output or analog input.
RA2/AN2/VREF-/CVREF
bit 2
TTL
Input/output or analog input or VREF-.
RA3/AN3/VREF+
bit 3
TTL
Input/output or analog input or VREF+.
RA4/T0CKI/C1OUT
bit 4
ST
Input/output or external clock input for Timer0. Output is
open-drain type.
RA5/AN4/LVDIN/SS/C2OUT
bit 5
TTL
Input/output or slave select input for synchronous serial port or
analog input.
OSC2/CLKO/RA6
bit 6
ST
Input/output, connects to crystal or resonator, oscillator output or
1/4 the frequency of OSC1 and denotes the instruction cycle in
RC mode.
OSC1/CLKI/RA7
bit 7
ST/CMOS(1) Input/output, connects to crystal or resonator or oscillator input.
Legend: TTL = TTL input, ST = Schmitt Trigger input
Note 1:
This buffer is a Schmitt Trigger input when configured in RC Oscillator mode and a CMOS input otherwise.
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
RA7
RA6
RA5
RA4
RA3
RA2
RA1
RA0
xx0x 0000
uu0u 0000
85h
TRISA
PORTA Data Direction Register
1111 1111
9Fh
ADCON1
ADFM
ADCS2
VCFG1 VCFG0 PCFG3
PCFG2
PCFG1
PCFG0
0000 0000
9Ch
CMCON
C2OUT
C1OUT
C2INV
C1INV
CIS
CM2
CM1
CM0
0000 0111
9Dh
CVRCON
CVREN CVROE
CVRR
—
CVR3
CVR2
CVR1
CVR0
000- 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 PCFG2:PCFG0 = 100, 101, 11x.
