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Overview

Devices in the PIC18F2450/4450 family incorporate a different oscillator and microcontroller clock system than the non-USB PIC18F devices. The addition of the USB module, with its unique requirements for a stable clock source, make it necessary to provide a separate clock source that is compliant with both USB low-speed and full-speed specifications.

Universal Serial Bus Features:

? USB V2.0 Compliant

? Low Speed (1.5 Mb/s) and Full Speed (12 Mb/s)

? Supports Control, Interrupt, Isochronous and Bulk Transfers

? Supports Up to 32 Endpoints (16 bidirectional)

? 256-Byte Dual Access RAM for USB

? On-Chip USB Transceiver with On-Chip Voltage Regulator

? Interface for Off-Chip USB Transceiver

Power-Managed Modes:

? Run: CPU on, Peripherals on

? Idle: CPU off, Peripherals on

? Sleep: CPU off, Peripherals off

? Idle mode Currents Down to 5.8 ¦ÌA Typical

? Sleep mode Currents Down to 0.1 ¦ÌA Typical

? Timer1 Oscillator: 1.8 ¦ÌA Typical, 32 kHz, 2V

? Watchdog Timer: 2.1 ¦ÌA Typical

? Two-Speed Oscillator Start-up

Flexible Oscillator Structure:

? Four Crystal modes, including High-Precision PLL for USB

? Two External Clock modes, up to 48 MHz

? Internal 31 kHz Oscillator

? Secondary Oscillator using Timer1 @ 32 kHz

? Dual Oscillator Options allow Microcontroller and USB module to Run at Different Clock Speeds

? Fail-Safe Clock Monitor:

- Allows for safe shutdown if any clock stops

Peripheral Highlights:

? High-Current Sink/Source: 25 mA/25 mA

? Three External Interrupts

? Three Timer modules (Timer0 to Timer2)

? Capture/Compare/PWM (CCP) module:

- Capture is 16-bit, max. resolution 5.2 ns

- Compare is 16-bit, max. resolution 83.3 ns

- PWM output: PWM resolution is 1 to 10-bit

? Enhanced USART module:

- LIN bus support

? 10-Bit, Up to 13-Channel Analog-to-Digital Converter module (A/D):

- Up to 100 ksps sampling rate

- Programmable acquisition time

Special Microcontroller Features:

? C Compiler Optimized Architecture with Optional Extended Instruction Set

? Flash Memory Retention: > 40 Years

? Self-Programmable under Software Control

? Priority Levels for Interrupts

? 8 x 8 Single-Cycle Hardware Multiplier

? Extended Watchdog Timer (WDT):

- Programmable period from 4 ms to 131s

? Programmable Code Protection

? Single-Supply In-Circuit Serial Programming? (ICSP?) via Two Pins

? In-Circuit Debug (ICD) via Two Pins

? Optional Dedicated ICD/ICSP Port (44-pin TQFP devices only)

? Wide Operating Voltage Range (2.0V to 5.5V)