PIC18F2450-I/SO Microchip Technology, PIC18F2450-I/SO Datasheet - Page 29

• Manufacturer Part Number: PIC18F2450-I/SO
• Description: IC PIC MCU FLASH 8KX16 28SOIC
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F2450-I/SO

• Program Memory Type: FLASH
• Program Memory Size: 16KB (8K x 16)
• Package / Case: 28-SOIC (7.5mm Width)
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 48MHz
• Connectivity: UART/USART, USB
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 23
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 10x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 768 B
• Interface Type: EUSART/USB
• Maximum Clock Frequency: 48 MHZ
• Number Of Programmable I/os: 23
• Number Of Timers: 3
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, ICE4000, DM163014, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit
• Package: 28SOIC W
• Device Core: PIC
• Family Name: PIC18
• Maximum Speed: 48 MHz
• A/d Bit Size: 10 bit
• A/d Channels Available: 10
• Height: 2.31 mm
• Length: 17.87 mm
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2 V
• Width: 7.49 mm
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC164322 - MODULE SOCKET MPLAB PM3 28/44QFNDM163025 - PIC DEM FULL SPEED USB DEMO BRD
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

2.2.5
The PIC18F2450/4450 devices include an internal RC
oscillator (INTRC) which provides a nominal 31 kHz out-
put. INTRC is enabled if it is selected as the device clock
source; it is also enabled automatically when any of the
following are enabled:
• Power-up Timer
• Fail-Safe Clock Monitor
• Watchdog Timer
• Two-Speed Start-up
These features are discussed in greater detail in
Section 18.0 “Special Features of the CPU”.
2.2.5.1
When the internal oscillator is used as the micro-
controller clock source, one of the other oscillator
modes (External Clock or External Crystal/Resonator)
must be used as the USB clock source. The choice of
USB clock source is determined by the particular
internal oscillator mode.
There are four distinct modes available:
1.
2.
3.
4.
Of these four modes, only INTIO mode frees up an
additional pin (OSC2/CLKO/RA6) for port I/O use.
© 2007 Microchip Technology Inc.
INTHS mode: The USB clock is provided by the
oscillator in HS mode.
INTXT mode: The USB clock is provided by the
oscillator in XT mode.
INTCKO mode: The USB clock is provided by an
external clock input on OSC1/CLKI; the OSC2/
CLKO pin outputs F
INTIO mode: The USB clock is provided by an
external clock input on OSC1/CLKI; the OSC2/
CLKO pin functions as a digital I/O (RA6).
INTERNAL OSCILLATOR
Internal Oscillator Modes
OSC
/4.
Preliminary
2.3
When the PIC18F2450/4450 is used for USB
connectivity, it must have either a 6 MHz or 48 MHz
clock for USB operation, depending on whether Low-
Speed or Full-Speed mode is being used. This may
require some forethought in selecting an oscillator
frequency and programming the device.
The full range of possible oscillator configurations
compatible with USB operation is shown in Table 2-3.
2.3.1
The USB clock for Low-Speed mode is derived from
the primary oscillator chain and not directly from the
PLL. It is divided by 4 to produce the actual 6 MHz
clock. Because of this, the microcontroller can only use
a clock frequency of 24 MHz when the USB module is
active and the controller clock source is one of the
primary oscillator modes (XT, HS or EC, with or without
the PLL).
This restriction does not apply if the microcontroller
clock source is the secondary oscillator or internal
oscillator.
2.3.2
The
asynchronously with respect to the microcontroller core
and other peripherals. This means that applications can
use the primary oscillator for the USB clock while the
microcontroller runs from a separate clock source at a
lower speed. If it is necessary to run the entire application
from only one clock source, full-speed operation provides
a greater selection of microcontroller clock frequencies.
USB
Oscillator Settings for USB
PIC18F2450/4450
LOW-SPEED OPERATION
RUNNING DIFFERENT USB AND
MICROCONTROLLER CLOCKS
module,
in
either
mode,
DS39760C-page 27
can
run