
9.0 System Wake-Up Control (SWC)
(Continued)
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Figure 47. SWC Block Diagram
9.2
FUNCTIONAL DESCRIPTION
9.2.1
External Events
General-Purpose Input/Output Events
The PC8741x devices support 16 V
SB
-powered General-Purpose Input/Output events through ports GPIOE10-17 and
GPIOE40-47. V
DD
- and V
SB
-powered signals can be connected to the GPIO pins to become sources of external events. A
V
DD
-powered signal used to generate an event is internally disabled (for event generation) while V
DD
power is off and also
for 1 second after V
DD
power is restored. This prevents the detection of false events during power transitions and while the
signal driver is unpowered. For the same reasons, a V
SB
-powered signal used to generate an event is enabled only 1 second
after the V
SB
power is on. (When V
SB
is off, the whole SWC module is disabled.)
Each GPIOE pin has programmable polarity and an optional 16 ms debouncer (see Figure 48). The debouncer is enabled
after the reset but can be disabled by software.
A GPIO event can generate the system interrupts (IRQ and SMI) if the event is enabled and routed to the specific interrupt.
The status, event enable and pending event routing bits to IRQ and SMI are implemented in the GPIO Ports module (see
Section 7.3 on page 137). The status bit is set when an event of the programmed type (edge or level) is detected.
A GPIO event can also generate the Power Management signals (the SCI interrupt, the ONCTL power supply control and
the PWBTOUT signal). The status, event enable and wake-up state enable bits are implemented in the SWC module (see
Figures 48 and 50).
External
Events
IRQ
SIOSMI
Interrupt
Routing
Control
SIOSCI
SCI
Interrupt
Enable
ONCTL
PWBTOUT
4 Sec.
Override
and
Crowbar
Power
Management
Signals
Enable
LED1
LED2
LED
Control
Power Active Timers
Debounce
and
Detection
Event
Status
31
Internal
Events
7
24
Power Button
V
DD
, V
SB
Status
Current Sleep State
2
1 Hz Clock
Sleep
State
Converter
4
2
SLP_TYPx
SLP_EN
SPLS3
SLPS5
SWC
Watchdog
1 Min. Clock
WDO
Legacy
Power
Button
S5
Power Button