PIC16F7X7
TABLE 5-1:
PORTA FUNCTIONS
Name
Bit#
Buffer
Function
RA0/AN0
bit 0
bit 1
bit 2
bit 3
bit 4
TTL
TTL
TTL
TTL
ST
Input/output or analog input.
Input/output or analog input.
RA1/AN1
RA2/AN2/VREF-/CVREF
RA3/AN3/VREF+
RA4/T0CKI/C1OUT
Input/output or analog input or VREF-.
Input/output or analog input or VREF+.
Input/output or external clock input for Timer0. Output is
open-drain type.
RA5/AN4/LVDIN/SS/C2OUT bit 5
TTL
ST
Input/output or slave select input for synchronous serial port or
analog input.
OSC2/CLKO/RA6
bit 6
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.
TABLE 5-2:
SUMMARY OF REGISTERS ASSOCIATED WITH PORTA
Value on
all other
Resets
Value on:
POR, BOR
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
05h
PORTA
TRISA
RA7
RA6
RA5
RA4
RA3
RA2
RA1
RA0
xx0x 0000 uu0u 0000
1111 1111 1111 1111
85h
PORTA Data Direction Register
9Fh
ADCON1
CMCON
ADFM ADCS2 VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 0000 0000 0000 0000
9Ch
C2OUT C1OUT C2INV C1INV
CIS
CM2
CM1
CM0
0000 0111 0000 0111
9Dh
CVRCON CVREN CVROE CVRR
—
CVR3
CVR2
CVR1
CVR0 000- 0000 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.
2004 Microchip Technology Inc.
DS30498C-page 55
MICROCHIP [ MICROCHIP ]
