PIC16LF1454 Datasheet, PDF (309/418 Pages) Microchip Technology – 14/20-Pin Flash, 8-Bit USB Microcontrollers with XLP Technology

PIC16(L)F1454/5/9
26.0 UNIVERSAL SERIAL BUS
(USB)
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 USB information is provided in Section 26.1
“Overview” only for application design reference.
Designers are encouraged to refer to the official
specification published by the USB Implementers
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.
26.1 Overview
This device contains a full-speed and low-speed
compatible USB Serial Interface Engine (SIE) that
allows fast communication between any USB host and
the microcontroller. 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
endpoint memory usage within the USB RAM space.
Figure 26-1 presents a general overview of the USB
peripheral and its features.
FIGURE 26-1:
USB PERIPHERAL AND OPTIONS
USB PIC^® Microcontroller
3.3V LDO Regulator ⁽²⁾
FSEN
UPUEN
USB Clock from the
Oscillator Module
USB Control and
Configuration
(3)
512 byte
USB RAM
USB
SIE
P
Internal Pull-ups
P
Transceiver
FS
EN
VUSB3V3
(1) VDD
Vcap
External 3.3V
Supply
USB
D+
D-
Note 1: Possible optional setup for LF parts only. F parts should use internal LDO to power VUSB3V3.
2: On F devices the regulator is powered by Vdd. On LF devices the regulator is internally bypassed to Vdd.
3: 496 bytes accessible in both linear and banked data space. 16 bytes accessible in access data space only.
 2012 Microchip Technology Inc.
Preliminary
DS41639A-page 309