PIC18F25K20T-ISS Datasheet, PDF (39/456 Pages) Microchip Technology – 28/40/44-Pin Flash Microcontrollers with nanoWatt XLP Technology

PIC18F2XK20/4XK20
FIGURE 2-7:
CLOCK SWITCH TIMING
High Speed Low Speed
Old Clock
Start-up Time⁽¹⁾
New Clock
New Clk Ready
IRCF <2:0> Select Old
Select New
System Clock
Clock Sync
Running
Low Speed High Speed
Old Clock
Start-up Time⁽¹⁾
New Clock
New Clk Ready
IRCF <2:0> Select Old
Select New
System Clock
Clock Sync
Running
Note 1: Start-up time includes TOST (1024 TOSC) for external clocks, plus TPLL (approx. 2 ms) for HSPLL mode.
 2010 Microchip Technology Inc.
DS41303G-page 39