Datasheet

PIC18F2450/4450
DS39760D-page 28 © 2008 Microchip Technology Inc.
TABLE 2-3: OSCILLATOR CONFIGURATION OPTIONS FOR USB OPERATION
Input Oscillator
Frequency
PLL Division
(PLLDIV2:PLLDIV0)
Clock Mode
(FOSC3:FOSC0)
MCU Clock Division
(CPUDIV1:CPUDIV0)
Microcontroller
Clock Frequency
48 MHz N/A
(1)
EC, ECIO
None (00)48MHz
÷2 (01) 24 MHz
÷3 (10)16MHz
÷4 (11)12MHz
48 MHz ÷12 (111)
EC, ECIO
None (00)48MHz
÷2 (01) 24 MHz
÷3 (10)16MHz
÷4 (11)12MHz
ECPLL, ECPIO
÷2 (00)48MHz
÷3 (01)32MHz
÷4 (10) 24 MHz
÷6 (11)16MHz
40 MHz ÷10 (110)
EC, ECIO
None (00)40MHz
÷2 (01)20MHz
÷3 (10) 13.33 MHz
÷4 (11)10MHz
ECPLL, ECPIO
÷2 (00)48MHz
÷3 (01)32MHz
÷4 (10) 24 MHz
÷6 (11)16MHz
24 MHz ÷6 (101)
HS, EC, ECIO
None (00) 24 MHz
÷2 (01)12MHz
÷3 (10)8MHz
÷4 (11)6MHz
HSPLL, ECPLL, ECPIO
÷2 (00)48MHz
÷3 (01)32MHz
÷4 (10) 24 MHz
÷6 (11)16MHz
20 MHz ÷5 (100)
HS, EC, ECIO
None (00)20MHz
÷2 (01)10MHz
÷3 (10)6.67MHz
÷4 (11)5MHz
HSPLL, ECPLL, ECPIO
÷2 (00)48MHz
÷3 (01)32MHz
÷4 (10) 24 MHz
÷6 (11)16MHz
16 MHz ÷4 (011)
HS, EC, ECIO
None (00)16MHz
÷2 (01)8MHz
÷3 (10)5.33MHz
÷4 (11)4MHz
HSPLL, ECPLL, ECPIO
÷2 (00)48MHz
÷
3 (01)32MHz
÷4 (10) 24 MHz
÷6 (11)16MHz
Legend: All clock frequencies, except 24 MHz, are exclusively associated with full-speed USB operation (USB clock of 48 MHz).
Bold is used to highlight clock selections that are compatible with low-speed USB operation (system clock of 24 MHz,
USB clock of 6 MHz).
Note 1: Only valid when the USBDIV Configuration bit is cleared.