PIC16LF1454 Datasheet, PDF (323/418 Pages) Microchip Technology – 14/20-Pin Flash, 8-Bit USB Microcontrollers with XLP Technology

26.7 Oscillator
The USB module has specific clock requirements. For
full-speed operation, the clock source must be 48 MHz.
Even so, the microcontroller core and other peripherals
are not required to run at that clock speed. Available
clocking options are described in detail in Section 5.4
“USB Operation”.
26.8 Interrupt-On-Change for D+/D-
Pins
The microcontroller has interrupt-on-change function-
ality on both D+ and D- data pins, which allows the
device to detect voltage level changes when first con-
nected to a USB host/hub. This feature is not available
when the USB module is enabled.
The USB host/hub has 15K pull-down resistors on the
D+ and D- pins. When the microcontroller attaches to
the bus, the D+ and D- pins can detect voltage
changes. External resistors are needed for each pin to
maintain a high state on the pins when the
microcontroller is detached.
The USB module must be disabled (USBEN = 0) for the
interrupt-on-change to function. Enabling the USB
module (USBEN = 1) will automatically disable the
interrupt-on-change for D+ and D- pins. Refer to
Section 13.0 “Interrupt-On-Change” for more detail.
26.9 USB Firmware and Drivers
Microchip provides a number of application-specific
resources, such as USB firmware and driver support.
Refer to www.microchip.com for the latest firmware and
driver support.
PIC16(L)F1454/5/9
 2012 Microchip Technology Inc.
Preliminary
DS41639A-page 323