PIC18F2450-I/SO Microchip Technology, PIC18F2450-I/SO Datasheet - Page 26

• 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

PIC18F2450/4450
2.2.1
Because of the unique requirements of the USB
module, a different approach to clock operation is
necessary. In previous PIC
and peripheral clocks were driven by a single oscillator
source; the usual sources were primary, secondary or
the internal oscillator. With PIC18F2450/4450 devices,
the primary oscillator becomes part of the USB module
and cannot be associated to any other clock source.
Thus, the USB module must be clocked from the
primary clock source; however, the microcontroller
core and other peripherals can be separately clocked
from the secondary or internal oscillators as before.
FIGURE 2-1:
DS39760C-page 24
T1OSO
T1OSI
OSC2
OSC1
OSCILLATOR MODES AND
USB OPERATION
Primary Oscillator
Secondary Oscillator
PIC18F2450/4450 CLOCK DIAGRAM
XT, HS, EC, ECIO
Sleep
T1OSCEN
Enable
Oscillator
®
microcontrollers, all core
Internal RC Oscillator
31.25 kHz
÷ 4
÷ 3
÷ 2
÷ 1
CPUDIV<1:0>
÷ 12
÷ 10
÷ 6
÷ 5
÷ 4
÷ 3
÷ 2
÷ 1
Preliminary
PIC18F2450/4450
PLLDIV<2:0>
11
10
01
00
111
110
101
100
011
010
001
000
HSPLL, ECPLL,
XTPLL, ECPIO
(4 MHz Input Only)
OSCCON<6:4>
Because of the timing requirements imposed by USB,
an internal clock of either 6 MHz or 48 MHz is required
while the USB module is enabled. Fortunately, the
microcontroller and other peripherals are not required
to run at this clock speed when using the primary
oscillator. There are numerous options to achieve the
USB module clock requirement and still provide flexi-
bility for clocking the rest of the device from the primary
oscillator source. These are detailed in Section 2.3
“Oscillator Settings for USB”.
96 MHz
PLL
÷ 6
÷ 4
÷ 3
÷ 2
CPUDIV<1:0>
11
10
01
00
FOSC3:FOSC0
÷ 2
Internal Oscillator
USBDIV
1
0
FOSC3:FOSC0
0
1
Primary
Clock
T1OSC
© 2007 Microchip Technology Inc.
USB Clock Source
÷ 4
Clock Source Option
for other Modules
WDT, PWRT, FSCM
and Two-Speed Start-up
Control
Clock
OSCCON<1:0>
FSEN
1
0
IDLEN
Peripherals
Peripheral
USB
CPU