Production Data
WM8321
TRANSITION
SEQUENCE
EVENT
RTC alarm
NOTES
ON SOURCE /
OFF SOURCE
ON (see note 1)
An ON request occurs if the RTC Alarm occurs ON_TRANS, ON_RTC_ALM
in the OFF power state. See Section 20.
GPIO ON request
O¯¯N pin request
Requires a GPIO to be configured as “Power
On request” or “Power On/Off request”. See
Section 21.
ON_TRANS, ON_GPIO
Requires the O¯¯N pin to be configured to
generate ON request. See Section 11.6.
ON_TRANS, ON_ON_PIN
WAKE
Software WAKE
Writing CHIP_SLP = 0. See Table 2.
ON_SW_REQ
Watchdog timeout
Requires the Watchdog to be configured to
generate WAKE request. See Section 25.
ON_WDOG_TO
RTC alarm
A WAKE request occurs if the RTC Alarm
occurs in the SLEEP power state. See
Section 20.
ON_RTC_ALM
GPIO WAKE request
PVDD undervoltage
Requires a GPIO to be configured as
“Sleep/Wake request”. See Section 21.
ON_GPIO
Requires the PVDD monitor circuit to be
configured to generate WAKE request. See
Section 24.4.
ON_SYSLO
O¯¯N pin request
Requires the O¯¯N pin to be configured to
generate WAKE request. See Section 11.6.
ON_ON_PIN
OFF
Watchdog timeout
Requires the Watchdog to be configured to
generate Device Reset. See Section 25.
RESET_WDOG
(See note 2)
Hardware Reset
Software Reset
See Section 24.
RESET_HW
(See note 2)
See Section 24.
RESET_SW
(See note 2)
Power Management
Undervoltage Reset
Configurable option for each LDO/DC-DC
converter. See Section 15.
RESET_CNV_UV
(See note 2)
Software OFF request
ON pin request
Writing CHIP_ON = 0. See Table 2.
OFF_SW_REQ
OFF_ON_PIN
Requires the O¯¯N pin to be configured to
generate OFF request. See Section 11.6.
Thermal shutdown
PVDD undervoltage
See Section 26.
OFF_THERR
OFF_PVDD
Requires the PVDD monitor circuit to be
configured to generate OFF request. See
Section 24.4.
PVDD shutdown
PVDD has fallen below the SHUTDOWN
threshold. See Section 24.4.
OFF_PVDD
GPIO OFF request
Power Sequence failure
Requires a GPIO to be configured as “Power
On/Off request”. See Section 21.
OFF_GPIO
DC-DC converters, LDOs or CLKOUT circuits
have failed to start up within the permitted time.
OFF_PWR_SEQ
Internal LDO error
Error condition detected in LDO13
Writing CHIP_SLP = 1. See Table 2.
OFF_INTLDO_ERR
See note 3
SLEEP
Software SLEEP request
GPIO SLEEP request
Requires a GPIO to be configured as “Sleep
request” or “Sleep/Wake request”. See
Section 21.
See note 3
Table 3 Power State Transition Events
Notes:
1. An ON sequence is only permitted when the supply voltage PVDD exceeds a programmable threshold VSYSOK. See
Section 24.4 for details of PVDD voltage monitoring.
2. These Reset conditions result in an OFF transition followed by an ON transition. These events are recorded as Reset
events in the ‘ON Source’ register.
3. SLEEP events are not recorded in the ‘OFF Source’ register.
PD, February 2012, Rev 4.0
35
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
