PIC16F916-I/SO Microchip Technology Inc., PIC16F916-I/SO Datasheet - Page 73

• Manufacturer Part Number: PIC16F916-I/SO
• Description: 28 PIN, 14 KB FLASH, 352 RAM, 25 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F916-I/SO

• A/d Inputs: 5-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 5 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 25
• Interface: I2C/SPI/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 28-pin SOIC
• Programmable Memory: 14K Bytes
• Ram Size: 352 Bytes
• Speed: 20 MHz
• Timers: 2-8-bit, 1-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

4.2
Clock source modes can be classified as external or
internal.
• External clock modes rely on external circuitry for
• Internal clock sources are contained internally
The system clock can be selected between external or
internal clock sources via the System Clock Selection
(SCS) bit (see Section 4.5 “Clock Switching”).
4.3
4.3.1
If the PIC16F917/916/914/913 is configured for LP, XT
or HS modes, the Oscillator Start-up Timer (OST)
counts 1024 oscillations from the OSC1 pin, following a
Power-on Reset (POR), and the Power-up Timer
(PWRT) has expired (if configured), or a wake-up from
Sleep. During this time, the program counter does not
increment and program execution is suspended. The
OST ensures that the oscillator circuit, using a quartz
crystal resonator or ceramic resonator, has started and
is
PIC16F917/916/914/913. When switching between
clock sources a delay is required to allow the new clock
to stabilize. These oscillator delays are shown in
Table 4-1.
© 2005 Microchip Technology Inc.
the clock source. Examples are oscillator modules
(EC mode), quartz crystal resonators or ceramic
resonators (LP, XT and HS modes), and
Resistor-Capacitor (RC mode) circuits.
within the PIC16F917/916/914/913. The
PIC16F917/916/914/913 has two internal oscilla-
tors: the 8 MHz High-Frequency Internal Oscilla-
tor (HFINTOSC) and 31 kHz Low-Frequency
Internal Oscillator (LFINTOSC).
providing
Clock Source Modes
External Clock Modes
OSCILLATOR START-UP TIMER
(OST)
a
stable
system
clock
to
Preliminary
the
PIC16F917/916/914/913
4.3.1.1
An exception to this is when the device is put to Sleep
while the following conditions are true:
• LP is the selected primary oscillator mode.
• T1OSCEN = 1 (Timer1 oscillator is enabled).
• SCS = 0 (oscillator mode is defined by
• OSTS = 1 (device is running from primary system
For this case, the OST is not necessary after a wake-up
from Sleep, since Timer1 continues to run during Sleep
and uses the same LP oscillator circuit as its clock
source. For these devices, this case is typically seen
when the LCD module is running during Sleep.
In applications where the OSCTUNE register is used to
shift the F
expect the F
In this case, the frequency may shift gradually toward
the new value. The time for this frequency shift is less
than eight cycles of the base frequency.
Table 4-1 shows examples where the oscillator delay is
invoked.
In order to minimize latency between external oscillator
start-up and code execution, the Two-Speed Clock
Start-up mode can be selected (see Section 4.6
“Two-Speed Clock Start-up Mode”).
FOSC<2:0>).
clock).
Note:
INTOSC
When the OST is invoked, the WDOG is
held in Reset, because the WDOG ripple
counter is used by the OST to perform the
oscillator delay count. When the OST
count has expired, the WDOG will begin
counting (if enabled).
INTOSC
Special Case
frequency, the application should not
frequency to stabilize immediately.
DS41250E-page 71