PIC12F683-I/MD Microchip Technology Inc., PIC12F683-I/MD Datasheet - Page 27

• Manufacturer Part Number: PIC12F683-I/MD
• Description: 8 PIN, 3.5KB FLASH, 128 RAM, 6 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC12F683-I/MD

• A/d Inputs: 4-Channel, 10-Bit
• Comparators: 1
• Cpu Speed: 5 MIPS
• Eeprom Memory: 256 Bytes
• Frequency: 20 MHz
• Input Output: 6
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 8-Pin PDIP
• Programmable Memory: 3.5K Bytes
• Ram Size: 128 Bytes
• Serial Interface: None
• 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

3.5.2
The Oscillator Start-up Time-out Status (OSTS) bit
(OSCCON<3>) indicates whether the system clock is
running from the external clock source, as defined by
the FOSC bits, or from internal clock source. In partic-
ular, OSTS indicates that the Oscillator Start-up Timer
(OST) has timed out for LP, XT or HS modes.
3.6
Two-Speed Start-up mode provides additional power
savings by minimizing the latency between external
oscillator start-up and code execution. In applications
that make heavy use of the Sleep mode, Two-Speed
Start-up will remove the external oscillator start-up time
from the time spent awake and can reduce the overall
power consumption of the device.
This mode allows the application to wake-up from
Sleep, perform a few instructions using the INTOSC as
the clock source and go back to Sleep without waiting
for the primary oscillator to become stable.
When the PIC12F683 is configured for LP, XT or HS
modes, the Oscillator Start-up Timer (OST) is enabled
(see
(OST)”). The OST timer will suspend program execu-
tion until 1024 oscillations are counted. Two-Speed
Start-up mode minimizes the delay in code execution
by operating from the internal oscillator as the OST is
counting. When the OST count reaches 1024 and the
OSTS bit (OSCCON<3>) is set, program execution
switches to the external oscillator.
 2004 Microchip Technology Inc.
Note:
Section 3.3.1
Two-Speed Clock Start-up Mode
OSCILLATOR START-UP TIME-OUT
STATUS BIT
Executing a SLEEP instruction will abort
the oscillator start-up time and will cause
the OSTS bit (OSCCON<3>) to remain
clear.
“Oscillator
Start-up
Timer
Preliminary
3.6.1
Two-Speed Start-up mode is configured by the
following settings:
• IESO = 1 (CONFIG<10>) Internal/External Switch
• SCS = 0.
• FOSC configured for LP, XT or HS mode.
Two-Speed Start-up mode is entered after:
• Power-on Reset (POR) and, if enabled, after
• Wake-up from Sleep.
If the external clock oscillator is configured to be any-
thing other than LP, XT or HS mode, then Two-Speed
Start-up is disabled. This is because the external clock
oscillator does not require any stabilization time after
POR or an exit from Sleep.
3.6.2
1.
2.
3.
4.
5.
6.
7.
Over bit.
PWRT has expired, or
Wake-up from Power-on Reset or Sleep.
Instructions begin execution by the internal
oscillator at the frequency set in the IRCF bits
(OSCCON<6:4>).
OST enabled to count 1024 clock cycles.
OST timed out, wait for falling edge of the
internal oscillator.
OSTS is set.
System clock held low until the next falling edge
of new clock (LP, XT or HS mode).
System clock is switched to external clock
source.
TWO-SPEED START-UP MODE
CONFIGURATION
TWO-SPEED START-UP
SEQUENCE
PIC12F683
DS41211B-page 25