PIC18F44K20-E/MV Microchip Technology, PIC18F44K20-E/MV Datasheet - Page 38

• Manufacturer Part Number: PIC18F44K20-E/MV
• Description: 16KB, Flash, 768bytes-RAM, 36I/O, 8-bit Family,nanowatt XLP 40 UQFN 5x5x0.5mm TU
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 18Fr

Specifications of PIC18F44K20-E/MV

• Processor Series: PIC18
• Core: PIC18F
• Data Bus Width: 8 bit
• Program Memory Type: Flash
• Program Memory Size: 8 KB
• Data Ram Size: 512 B
• Interface Type: I2C, SPI, SCI, USB, MSSP, RJ11
• Maximum Clock Frequency: 64 MHz
• Number Of Programmable I/os: 35
• Number Of Timers: 4
• Operating Supply Voltage: 1.8 V to 3.6 V
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Package / Case: UQFN-40
• Development Tools By Supplier: MPLAB Integrated Development Environment
• Minimum Operating Temperature: - 40 C
• Operating Temperature Range: - 40 C to + 125 C
• Supply Current (max): 30 uA
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 48MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 35
• Eeprom Size: 256 x 8
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 3.6 V
• Data Converters: A/D 14x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Lead Free Status / Rohs Status: Details

PIC18F2XK20/4XK20
2.10
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 HFINTOSC
as the clock source and go back to Sleep without
waiting for the primary oscillator to become stable.
When the Oscillator module is configured for LP, XT or
HS modes, the Oscillator Start-up Timer (OST) is
enabled (see Section 2.4.1 “Oscillator Start-up Timer
(OST)”). The OST will suspend program execution 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 of the OSCCON register is set, program
execution switches to the external oscillator.
2.10.1
Two-Speed Start-up mode is enabled when all of the
following settings are configured as noted:
• Two-Speed Start-up mode is enabled by setting
• SCS<1:0> (of the OSCCON register) = 00.
• FOSC<2:0> bits of the CONFIG1H Configuration
Two-Speed Start-up mode becomes active after:
• Power-on Reset (POR) and, if enabled, after
• Wake-up from Sleep.
If the external clock oscillator is configured to be
anything 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.
DS41303G-page 38
Note:
the IESO of the CONFIG1H Configuration register
is set. Fail-Safe mode (FCMEM = 1) also enables
two-speed by default.
register are configured for LP, XT or HS mode.
Power-up Timer (PWRT) has expired, or
Two-Speed Clock Start-up Mode
Executing a SLEEP instruction will abort
the oscillator start-up time and will cause
the OSTS bit of the OSCCON register to
remain clear.
TWO-SPEED START-UP MODE
CONFIGURATION
2.10.2
1.
2.
3.
4.
5.
6.
2.10.3
Checking the state of the OSTS bit of the OSCCON
register will confirm if the microcontroller is running
from the external clock source, as defined by the
FOSC<2:0> bits in CONFIG1H Configuration register,
or the internal oscillator. OSTS = 0 when the external
oscillator is not ready, which indicates that the system
is running from the internal oscillator.
Wake-up from Power-on Reset or Sleep.
Instructions begin executing by the internal
oscillator at the frequency set in the IRCF<2:0>
bits of the OSCCON register.
OST enabled to count 1024 external clock
cycles.
OST timed out. External clock is ready.
OSTS is set.
Clock switch finishes according to FIGURE 2-7:
“Clock Switch Timing”
TWO-SPEED START-UP
SEQUENCE
CHECKING TWO-SPEED CLOCK
STATUS
 2010 Microchip Technology Inc.