PIC16F747 Microchip Technology Inc., PIC16F747 Datasheet - Page 49

• Manufacturer Part Number: PIC16F747
• Description: 28/40/44-pin, 8-bit Cmos Flash Microcontrollers With 10-bit A/d And Nanowatt Technology
• Manufacturer: Microchip Technology Inc.

TABLE 4-4:
 2004 Microchip Technology Inc.
LP, XT, HS,
LP, XT, HS,
Note 1:
LP, XT, HS
Current
System
T1OSC,
EC, RC
EC, RC
T1OSC
T1OSC
INTRC,
INTRC
INTRC
Clock
If the new clock source is the INTOSC or INTOSC postscaler, then the IOFS bit will be set 4 ms (approx.)
after the clock change.
FOSC<2:0> = EC
FOSC<2:0> = RC
FOSC<2:0> = LP,
FOSC<2:0> = LP,
FOSC<2:0> = LP,
SCS bits<1:0>
(Due to Reset)
Modified to:
LP, XT, HS
XT or HS
XT or HS
(T1OSC)
CLOCK SWITCHING MODES
(INTRC)
XT, HS
10
01
00
00
00
or
1024 Clocks
1024 Clocks
8 Clocks of
8 Clocks of
8 Clocks of
8 Clocks of
LP, XT, HS
T1OSC
INTRC
Delay
RC
EC
or
+
OSTS
bit
0
0
1
1
1
IOFS
N/A
N/A
N/A
N/A
1
bit
(1)
T1RUN
bit
0
1
0
0
0
LP, XT, HS During the 1024 clocks,
LP, XT, HS When a Reset occurs, there is
Postscaler
INTOSC
INTOSC
System
T1OSC
INTRC
Clock
New
EC
RC
or
or
or
The internal RC oscillator
frequency is dependant upon
the IRCF bits.
T1OSCEN bit must be enabled.
program execution is clocked
from the secondary oscillator
until the primary oscillator
becomes stable.
no clock transition sequence.
Instruction
execution and/or peripheral
operation is suspended unless
Two-Speed Start-up mode is
enabled, after which the INTRC
will act as the system clock
until the Oscillator Start-up
Timer has expired.
PIC16F7X7
Comments
DS30498C-page 47