PIC18F44J50-I Datasheet, PDF (51/562 Pages) Microchip Technology – 28/44-Pin, Low-Power, High-Performance USB Microcontrollers

PIC18F46J50 FAMILY
4.3 Sleep Mode
The power-managed Sleep mode is identical to the
legacy Sleep mode offered in all other PIC devices. It is
entered by clearing the IDLEN bit (the default state on
device Reset) and executing the SLEEP instruction.
This shuts down the selected oscillator (Figure 4-5). All
clock source status bits are cleared.
Entering the Sleep mode from any other mode does not
require a clock switch. This is because no clocks are
needed once the controller has entered Sleep mode. If
the WDT is selected, the INTRC source will continue to
operate. If the Timer1 oscillator is enabled, it will also
continue to run.
When a wake event occurs in Sleep mode (by interrupt,
Reset or WDT time-out), the device will not be clocked
until the clock source selected by the SCS<1:0> bits
becomes ready (see Figure 4-6), or it will be clocked
from the internal oscillator if either the Two-Speed
Start-up or the FSCM are enabled (see Section 27.0
“Special Features of the CPU”). In either case, the
OSTS bit is set when the primary clock is providing the
device clocks. The IDLEN and SCS bits are not
affected by the wake-up.
FIGURE 4-5:
TRANSITION TIMING FOR ENTRY TO SLEEP MODE
OSC1
CPU
Clock
Peripheral
Clock
Sleep
Q1 Q2 Q3 Q4 Q1
Program
Counter
PC
PC + 2
FIGURE 4-6:
TRANSITION TIMING FOR WAKE FROM SLEEP (HSPLL)
OSC1
PLL Clock
Output
CPU Clock
Peripheral
Clock
Program
Counter
Q1
TOST⁽¹⁾
TPLL⁽¹⁾
Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Wake Event
PC
OSTS Bit Set
PC + 2
PC + 4
PC + 6
Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.
 2011 Microchip Technology Inc.
DS39931D-page 51