PIC16F627A_05 Datasheet, PDF (37/180 Pages) Microchip Technology – Flash-Based, 8-Bit CMOS Microcontrollers with nanoWatt Technology

PIC16F627A/628A/648A
TABLE 5-1: PORTA FUNCTIONS
Name
Function
Input
Type
Output
Type
Description
RA0/AN0
RA1/AN1
RA2/AN2/VREF
RA3/AN3/CMP1
RA4/T0CKI/CMP2
RA5/MCLR/VPP
RA0
AN0
RA1
AN1
RA2
AN2
VREF
RA3
AN3
CMP1
RA4
T0CKI
CMP2
RA5
MCLR
RA6/OSC2/CLKOUT
VPP
RA6
OSC2
CLKOUT
RA7/OSC1/CLKIN
RA7
OSC1
CLKIN
Legend: O = Output
— = Not used
TTL = TTL Input
ST
CMOS Bidirectional I/O port
AN
— Analog comparator input
ST
CMOS Bidirectional I/O port
AN
— Analog comparator input
ST
CMOS Bidirectional I/O port
AN
— Analog comparator input
—
AN VREF output
ST
CMOS Bidirectional I/O port
AN
— Analog comparator input
—
CMOS Comparator 1 output
ST
OD Bidirectional I/O port. Output is open drain type.
ST
— External clock input for TMR0 or comparator output
—
OD Comparator 2 output
ST
— Input port
ST
— Master clear. When configured as MCLR, this pin is an
active low Reset to the device. Voltage on MCLR/VPP must
not exceed VDD during normal device operation.
HV
— ^{Programming voltage input}
ST
CMOS Bidirectional I/O port
—
XTAL Oscillator crystal output. Connects to crystal resonator in
Crystal Oscillator mode.
—
CMOS In RC or INTOSC mode. OSC2 pin can output CLKOUT,
which has 1/4 the frequency of OSC1.
ST
CMOS Bidirectional I/O port
XTAL
— Oscillator crystal input. Connects to crystal resonator in
Crystal Oscillator mode.
ST
— External clock source input. RC biasing pin.
CMOS = CMOS Output
I
= Input
OD = Open Drain Output
P = Power
ST = Schmitt Trigger Input
AN = Analog
TABLE 5-2: 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
POR
Value on
All Other
Resets
05h
85h
1Fh
9Fh
Legend:
Note 1:
PORTA
RA7
RA6 _RA5⁽¹⁾ RA4
RA3
RA2
RA1
RA0 xxxx 0000 qqqu 0000
TRISA TRISA7 TRISA6 TRISA5 TRISA4 TRISA3 TRISA2 TRISA1 TRISA0 1111 1111 1111 1111
CMCON C2OUT C1OUT C2INV C1INV CIS CM2 CM1 CM0 0000 0000 0000 0000
VRCON VREN VROE VRR
—
VR3 VR2 VR1 VR0 000- 0000 000- 0000
- = Unimplemented locations read as ‘0’, u = unchanged, x = unknown, q = value depends on condition. Shaded cells
are not used for PORTA.
MCLRE configuration bit sets RA5 functionality.
© 2005 Microchip Technology Inc.
DS40044D-page 35