PIC16LF1454 Datasheet, PDF (300/418 Pages) Microchip Technology – 14/20-Pin Flash, 8-Bit USB Microcontrollers with XLP Technology

PIC16(L)F1454/5/9
25.9 Auto-Shutdown Control
Auto-shutdown is a method to immediately override the
CWG output levels with specific overrides that allow for
the safe shutdown of the circuit. The shutdown state
can be either cleared automatically or held until cleared
by software.
25.9.1 SHUTDOWN
The shutdown state can be entered by either of the
following two methods:
• Software generated
• External Input
25.9.1.1 Software Generated Shutdown
Setting the GxASE bit of the CWGxCON2 register will
force the CWG into the shutdown state.
When auto-restart is disabled, the shutdown state will
persist as long as the GxASE bit is set.
When auto-restart is enabled, the GxASE bit will clear
automatically and resume operation on the next rising
edge event. See Figure 25-6.
25.9.1.2 External Input Source
External shutdown inputs provide the fastest way to
safely suspend CWG operation in the event of a Fault
condition. When any of the selected shutdown inputs
go active, the CWG outputs will immediately go to the
selected override levels without a software delay. Any
combination of two input sources can be selected to
cause a shutdown condition. The sources are:
• async_C1OUT
• async_C2OUT
• CWG1FLT
Shutdown inputs are selected using the GxASDS0 and
GxASDS1 bits of the CWGxCON2 register
(Register 25-3).
Note:
Shutdown inputs are level sensitive, not
edge sensitive. The shutdown state can-
not be cleared, except by disabling
auto-shutdown, as long as the shutdown
input level persists.
25.10 Operation During Sleep
The CWG module operates independently from the
system clock and will continue to run during Sleep,
provided that the clock and input sources selected
remain active.
The HFINTOSC remains active during Sleep, provided
that the CWG module is enabled, the input source is
active, and the HFINTOSC is selected as the clock
source, regardless of the system clock source selected.
In other words, if the HFINTOSC is simultaneously
selected as the system clock and the CWG clock
source, when the CWG is enabled and the input source
is active, the CPU will go idle during Sleep, but the CWG
will continue to operate and the HFINTOSC will remain
active. This will have a direct effect on the Sleep mode
current.
DS41639A-page 300
Preliminary
 2012 Microchip Technology Inc.