PIC16F946 Datasheet, PDF (38/274 Pages) Microchip Technology – 64-Pin Flash-Based, 8-Bit CMOS Microcontrollers with LCD Driver and nanoWatt Technology

PIC16F946
3.1.1.8 RA7/OSC1/CLKI/T1OSI
Figure 3-8 shows the diagram for this pin. The
RA7/OSC1/CLKI/T1OSI pin is configurable to function
as one of the following:
• a general purpose I/O
• a crystal/resonator connection
• a clock input
• a TMR1 oscillator connection
FIGURE 3-8:
BLOCK DIAGRAM OF RA7/OSC1/CLKI/T1OSI
Data Bus
WR PORTA
From OSC1 Oscillator
Circuit
D
Q
CK Q
Data Latch
FOSC = 011
VDD
WR TRISA
FOSC = 10x
D
Q
CK Q
TRIS Latch
RD TRISA
FOSC = 10x
TTL
Input Buffer
RA7/OSC1/
CLKI/T1OSI
Pin
RD PORTA
TABLE 3-1: 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, BOR
Value on all
other
Resets
05h
PORTA
RA7
RA6
RA5
RA4
RA3
RA2
RA1
RA0 xxxx xxxx uuuu uuuu
10h
T1CON
T1GINV T1GE T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 0000 0000 uuuu uuuu
14h
SSPCON
WCOL SSPOV SSPEN
CKP
SSPM3 SSPM2 SSPM1 SSPM0 0000 0000 0000 0000
1Fh
ADCON0
ADFM VCFG1 VCFG0 CHS2
CHS1
CHS0 GO/DONE ADON 0000 0000 0000 0000
81h/181h OPTION_REG RBPU INTEDG T0CS
T0SE
PSA
PS2
PS1
PS0 1111 1111 1111 1111
85h
TRISA
TRISA7 TRISA6 TRISA5 TRISA4 TRISA3 TRISA2 TRISA1 TRISA0 1111 1111 1111 1111
91h
ANSEL
ANS7 ANS6 ANS5
ANS4
ANS3
ANS2
ANS1
ANS0 1111 1111 1111 1111
9Ch
CMCON0
C2OUT C1OUT C2INV C1INV
CIS
CM2
CM1
CM0 0000 0000 0000 0000
107h
11Ch
11Dh
LCDCON
LCDSE0⁽¹⁾
LCDSE1⁽¹⁾
LCDEN
SE7
SE15
SLPEN
SE6
SE14
WERR
SE5
SE13
VLCDEN
SE4
SE12
CS1
SE3
SE11
CS0
SE2
SE10
LMUX1
SE1
SE9
LMUX0
SE0
SE8
0001 0011 0001 0011
0000 0000 uuuu uuuu
0000 0000 uuuu uuuu
Legend: x = unknown, u = unchanged, – = unimplemented locations read as ‘0’. Shaded cells are not used by PORTA.
Note 1: This register is only initialized by a POR or BOR and is unchanged by other Resets.
DS41265A-page 36
Preliminary
© 2005 Microchip Technology Inc.