PIC18F-LF1XK50 MICROCHIP [Microchip Technology], PIC18F-LF1XK50 Datasheet - Page 251

• Manufacturer Part Number: PIC18F-LF1XK50
• Description: 20-Pin USB Flash Microcontrollers
• Manufacturer: MICROCHIP [Microchip Technology]

22.0
This section describes the details of the USB
peripheral. Because of the very specific nature of the
module, knowledge of USB is expected. Some
high-level
Section 22.10 “Overview of USB”
design reference. Designers are encouraged to refer to
the official specification published by the USB Imple-
menters Forum (USB-IF) for the latest information.
USB Specification Revision 2.0 is the most current
specification at the time of publication of this document.
FIGURE 22-1:
 2010 Microchip Technology Inc.
USB Clock from the
Note 1: The internal pull-up resistors should be disabled (UPUEN = 0) if external pull-up resistors are used.
Oscillator Module
USB Control and
USB RAM
256 byte
Configuration
UNIVERSAL SERIAL BUS
(USB)
2: PIC18F13K50/PIC18F14K50 only.
USB
PIC18F1XK50/PIC18LF1XK50 Family
3.3V LDO Regulator
information
USB PERIPHERAL AND OPTIONS
UPUEN
USB
SIE
FSEN
is
only for application
(2)
provided
Transceiver
Internal Pull-ups
FS
Preliminary
in
P
P
22.1
PIC18F1XK50/PIC18LF1XK50
full-speed and low-speed, compatible USB Serial Inter-
face Engine (SIE) that allows fast communication
between any USB host and the PIC
The SIE can be interfaced directly to the USB by
utilizing the internal transceiver.
Some special hardware features have been included to
improve performance. Dual access port memory in the
device’s data memory space (USB RAM) has been
supplied to share direct memory access between the
microcontroller core and the SIE. Buffer descriptors are
also provided, allowing users to freely program end-
point memory usage within the USB RAM space.
Figure 22-1
peripheral and its features.
V
USB
Overview of the USB Peripheral
D+
D-
PIC18F/LF1XK50
presents a general overview of the USB
Pull-ups
Optional
External
Speed)
(Full
(1)
Speed)
(Low
External 3.3V
devices
Supply
DS41350E-page 251
®
microcontroller.
USB Bus
contain
a