PIC18F-LF1XK50 MICROCHIP [Microchip Technology], PIC18F-LF1XK50 Datasheet - Page 238

• Manufacturer Part Number: PIC18F-LF1XK50
• Description: 20-Pin USB Flash Microcontrollers
• Manufacturer: MICROCHIP [Microchip Technology]

PIC18F/LF1XK50
19.4.1
This mode is unique among the three low-power Idle
modes, in that it does not disable the primary device
clock. For timing sensitive applications, this allows for
the fastest resumption of device operation with its more
accurate primary clock source, since the clock source
does not have to “warm-up” or transition from another
oscillator.
PRI_IDLE mode is entered from PRI_RUN mode by
setting the IDLEN bit and executing a SLEEP instruc-
tion. If the device is in another Run mode, set IDLEN
first, then clear the SCS bits and execute SLEEP.
Although the CPU is disabled, the peripherals continue
to be clocked from the primary clock source specified
by the FOSC<3:0> Configuration bits. The OSTS bit
remains set (see
When a wake event occurs, the CPU is clocked from the
primary clock source. A delay of interval T
required between the wake event and when code
execution starts. This is required to allow the CPU to
become ready to execute instructions. After the wake-
up, the OSTS bit remains set. The IDLEN and SCS bits
are not affected by the wake-up (see
FIGURE 19-3:
FIGURE 19-4:
DS41350E-page 238
CPU Clock
Peripheral
Program
Counter
CPU Clock
Peripheral
OSC1
Clock
Program
Counter
OSC1
Clock
PRI_IDLE MODE
Figure
Q1
Q1
TRANSITION TIMING FOR ENTRY TO IDLE MODE
TRANSITION TIMING FOR WAKE FROM IDLE TO RUN MODE
19-3).
Wake Event
Q2
PC
Q3
Figure
T
CSD
19-4).
Q4
CSD
Preliminary
Q1
is
PC + 2
PC
19.4.2
In SEC_IDLE mode, the CPU is disabled but the
peripherals continue to be clocked from the Timer1
oscillator. This mode is entered from SEC_RUN by set-
ting the IDLEN bit and executing a SLEEP instruction. If
the device is in another Run mode, set the IDLEN bit
first, then set the SCS<1:0> bits to ‘01’ and execute
SLEEP. When the clock source is switched to the
Timer1 oscillator, the primary oscillator is shut down,
the OSTS bit is cleared and the T1RUN bit is set.
When a wake event occurs, the peripherals continue to
be clocked from the Timer1 oscillator. After an interval
of T
cuting code being clocked by the Timer1 oscillator. The
IDLEN and SCS bits are not affected by the wake-up;
the Timer1 oscillator continues to run (see
4).
Note:
CSD
following the wake event, the CPU begins exe-
SEC_IDLE MODE
The Timer1 oscillator should already be
running prior to entering SEC_IDLE
mode. If the T1OSCEN bit is not set when
the SLEEP instruction is executed, the
main system clock will continue to operate
in the previously selected mode and the
corresponding IDLE mode will be entered
(i.e., PRI_IDLE or RC_IDLE).
Q2
 2010 Microchip Technology Inc.
Q3
Figure 19-
Q4