PIC16F1459-ESSQTP datasheet(323/418 Pages) MICROCHIP

323 / 418 page

 2012 Microchip Technology Inc.

Preliminary

DS41639A-page 323

PIC16(L)F1454/5/9

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.

PIC16F1459-ESSQTP Datasheet(PDF) 323 Page - Microchip Technology