Datasheet

ManualsBrandsMICROCHIP TECHNOLOGY ManualsMicrocontrollers, Microprocessors & QuartzesEmbedded microcontroller TQFP 64 (10x10) 8-Bit 40 MHz I/O number 52

 2003-2013 Microchip Technology Inc. DS30491D-page 29

PIC18F6585/8585/6680/8680

If the main oscillator is configured for HS mode with

PLL active, an oscillator start-up time (T

OST) plus an

additional PLL time-out (T

PLL) will occur. The PLL time-

out is typically 2 ms and allows the PLL to lock to the

main oscillator frequency. A timing diagram, indicating

the transition from the Timer1 oscillator to the main

oscillator for HS-PLL mode, is shown in Figure 2-10.

If the main oscillator is configured for EC mode with PLL

active, only the PLL time-out (T

PLL) will occur. The PLL

time-out is typically 2 ms and allows the PLL to lock to

the main oscillator frequency. A timing diagram, indicat-

ing the transition from the Timer1 oscillator to the main

oscillator for EC with PLL active, is shown in Figure 2-11.

FIGURE 2-10: TIMING FOR TRANSITION BETWEEN TIMER1 AND OSC1

(HS WITH PLL ACTIVE, SCS1 = 1)

FIGURE 2-11: TIMING FOR TRANSITION BETWEEN TIMER1 AND OSC1

(EC WITH PLL ACTIVE, SCS1 = 1)

Q4 Q1

Q1 Q2 Q3 Q4 Q1 Q2

OSC1

Internal System

SCS

(OSCCON<0>)

Program Counter

PC PC + 2

Note: TOST = 1024 TOSC (drawing not to scale).

T1OSI

Clock

TOST

PC + 4

TPLL

TOSC

TT1P

TSCS

PLL Clock

Input

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