PIC16F627A Datasheet, PDF (35/168 Pages) Microchip Technology – FLASH-Based 8-Bit CMOS Microcontrollers

PIC16F627A/628A/648A
FIGURE 5-4:
BLOCK DIAGRAM OF RA4/T0CKI PIN
Data
Bus
WR
PORTA
D
Q
CK Q
Data Latch
Comparator Mode = 110 (CMCON Reg.)
Comparator Output
1
0
D
Q
WR
TRISA
CK Q
TRIS Latch
VDD
N
RA4 Pin
Vss
Vss
RD TRISA
RD PORTA
TMR0 Clock Input
Schmitt Trigger
Input Buffer
Q
D
EN
FIGURE 5-5:
BLOCK DIAGRAM OF THE
RA5/MCLR/VPP PIN
MCLR
circuit
Program
mode
MCLRE (Configuration Bit)
MCLR Filter
HV Detect
Schmitt Trigger
Input Buffer
RA5/MCLR/VPP
Data
Bus
VSS
RD
TRISA
RD
PORTA
VSS
Q
D
EN
FIGURE 5-6:
BLOCK DIAGRAM OF
RA6/OSC2/CLKOUT PIN
From OSC1
CLKOUT(FOSC/4)
OSC
Circuit
VDD
1
WR
D
Q
0
PORTA
CK Q
(FOSC =
101, 111)
(2)
Data
Latch
VSS
WR
TRISA
RD
TRISA
D
Q
CK Q
TRIS Latch
FOSC =
011, 100, 110 ⁽¹⁾
RD PORTA
QD
EN
Schmitt
Trigger
Input Buffer
Note 1: INTOSC with RA6 = I/O or RC with RA6 = I/O.
2: INTOSC with RA6 = CLKOUT or RC with RA6 =
CLKOUT.
 2002 Microchip Technology Inc.
Preliminary
DS40044A-page 33