
RM0008
Power control (PWR)
Doc ID 13902 Rev 12
77/1096
5.4.2 Power
control/status register (PWR_CSR)
Address offset: 0x04
Reset value: 0x0000 0000 (not reset by wakeup from Standby mode)
Additional APB cycles are needed to read this register versus a standard APB read.
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Reserved
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Reserved
EWUP
Reserved
PVDO
SBF
WUF
rw
r
r
r
Bits 31:9 Reserved, always read as 0.
Bit 8
EWUP:
Enable WKUP pin
This bit is set and cleared by software.
0: WKUP pin is used for general purpose I/O. An event on the WKUP pin does not wakeup
the device from Standby mode.
1: WKUP pin is used for wakeup from Standby mode and forced in input pull down
configuration (rising edge on WKUP pin wakes-up the system from Standby mode).
Note: This bit is reset by a system Reset.
Bits 7:3 Reserved, always read as 0.
Bit 2
PVDO:
PVD output
This bit is set and cleared by hardware. It is valid only if PVD is enabled by the PVDE bit.
0: V
DD
/V
DDA
is higher than the PVD threshold selected with the PLS[2:0] bits.
1: V
DD
/V
DDA
is lower than the PVD threshold selected with the PLS[2:0] bits.
Note: The PVD is stopped by Standby mode. For this reason, this bit is equal to 0 after
Standby or reset until the PVDE bit is set.
Bit 1
SBF:
Standby flag
This bit is set by hardware and cleared only by a POR/PDR (power on reset/power down reset)
or by setting the CSBF bit in the
Power control register (PWR_CR)
0: Device has not been in Standby mode
1: Device has been in Standby mode
Bit 0
WUF:
Wakeup flag
This bit is set by hardware and cleared only by a POR/PDR (power on reset/power down
reset) or by setting the CWUF bit in the
Power control register (PWR_CR)
0: No wakeup event occurred
1: A wakeup event was received from the WKUP pin or from the RTC alarm
Note: An additional wakeup event is detected if the WKUP pin is enabled (by setting the
EWUP bit) when the WKUP pin level is already high.