Hibernate Mode Implementations; Externally Controlled Hibernate Mode Concept - Infineon XMC4000 Series Device Manual

2

Hibernate Mode Implementations

The two Hibernate Mode implementations, ECHM and ICHM, described in this section differ in the
way the core voltage generation control mechanism. However, the wake-up trigger detection
mechanism is the same for both Hibernate Mode implementations. The wakeup source can be digital
or analog, internal (RTC event) or external (input signal on an I/O). For more details please refer to
Table 1.
Table 1 Hibernate Wake-up Triggers
Trigger Source
RTC event
Watchdog of RTC external
crystal oscillator
Digital Input Signal
Analog Input Signal
VBAT Supply Level Detection
Various combinations of wake-up triggers are possible and a wide range of possible applications is
considered. The optimal selection of the Hibernate Mode and wake-up triggers application specific
requirements and availability of resources need to be taken in consideration.
Some system topologies may combine capabilities of both implementation of the Hibernate Mode and
can be applied interchangeably when required. However, only one of the Hibernate Modes can be
applied at the time.
2.1

Externally Controlled Hibernate Mode Concept

The system configuration assumes that the XMC4000 device acts as the power management master
of the system on PCB and is capable to switch off/on the external Voltage Regulator. The Hibernate
Mode is entered by switching off the power supply VDDP of the device with the HIB_IO_0 pin. The
HIB_IO_0 pin remains in control of the External Voltage Regulator after entering Hibernate Mode
since entire Hibernate Domain remains supplied with the VBAT voltage from an auxiliary supply
Device Guide
I/O Signals Description
n/a RTC Alarm or RTC Periodic Event.
n/a The RTC external crystal oscillator (OSC_ULP) watchdog
is capable of generating a wakeup trigger if the RTC clock
generated with external crystal, or, a direct external clock
stops unexpectedly
HIB_IO_0 Exclusive selection of one of the digital inputs. Depending
of an application a rising and/or falling edge of the signal
HIB_IO_1
may be selected as a wake-up trigger. For external
hibernate mode it is possible to combine Hibernate Control
and Wake-up function in the same digital IO. For availability
of the IOs please refer to the Data Sheet.
HIB_IO_0 Voltage threshold level crossing detection performed in the
Low Power Comparator (LPAC) module. Depending of an
HIB_IO_1
application a rising and/or falling voltage event may be
selected as a wake-up trigger. The level crossing detection
can be performed continuously, periodically, or, may be
triggered with an external digital signal. Multiple analog
channels may be used for the wake-up trigger detection.
For availability of the LPAC module please refer to the Data
Sheet.
VBAT VBAT voltage detection can be performed with LPAC
module. Depending of an application a rising and/or falling
voltage event may be selected as a wake-up trigger. The
VBAT
periodically, or, triggered with an external digital signal. For
availability of the LPAC module please refer to the Data
Sheet.
11
Hibernate Mode Implementations
input level can be
Hibernate
XMC4000 Family
performed continuously,
V1.0, 2013-04