Reset and clock control (RCC)
RM0365
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DocID025202 Rev 7
9.4.10 Control/status register (RCC_CSR)
Address: 0x24
Reset value: 0x0C00 0000, reset by system Reset, except reset flags by power Reset only.
Access: 0
≤
wait state
≤
3, word, half-word and byte access
Wait states are inserted in case of successive accesses to this register.
Bit 2
LSEBYP:
LSE oscillator bypass
Set and cleared by software to bypass oscillator in debug mode. This bit can be written only
when the external 32 kHz oscillator is disabled.
0: LSE oscillator not bypassed
1: LSE oscillator bypassed
Bit 1
LSERDY:
LSE oscillator ready
Set and cleared by hardware to indicate when the external 32 kHz oscillator is stable. After the
LSEON bit is cleared, LSERDY goes low after 6 external low-speed oscillator clock cycles.
0: LSE oscillator not ready
1: LSE oscillator ready
Bit 0
LSEON:
LSE oscillator enable
Set and cleared by software.
0: LSE oscillator OFF
1: LSE oscillator ON
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
LPWR
RSTF
WWDG
RSTF
IW
WDG
RSTF
SFT
RSTF
POR
RSTF
PIN
RSTF
OB
LRSTF
RMVF
V18PW
RRSTF
Res
Res
Res
Res
Res
Res
Res
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Res
Res
Res
Res
Res
Res
Res
Res
Res
Res
Res
Res
Res
Res
LSI
RDY
LSION
r
rw
Bit 31
LPWRSTF:
Low-power reset flag
Set by hardware when a Low-power management reset occurs.
Cleared by writing to the RMVF bit.
0: No Low-power management reset occurred
1: Low-power management reset occurred
For further information on low-power management reset, refer to
Bit 30
WWDGRSTF:
Window watchdog reset flag
Set by hardware when a window watchdog reset occurs.
Cleared by writing to the RMVF bit.
0: No window watchdog reset occurred
1: Window watchdog reset occurred