Low-, medium-, high- and XL-density reset and clock control (RCC) RM0008
119/1128 DocID13902 Rev 15
7.3.10 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: External low-speed 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: External low-speed 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: External 32 kHz oscillator not ready
1: External 32 kHz oscillator ready
Bit 0 LSEON: External low-speed oscillator enable
Set and cleared by software.
0: External 32 kHz oscillator OFF
1: External 32 kHz oscillator ON
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
LPWR
RSTF
WWDG
RSTF
IWDG
RSTF
SFT
RSTF
POR
RSTF
PIN
RSTF
Res.
RMVF
Reserved
rw rw rw rw rw rw rw
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Reserved
LSI
RDY
LSION
rrw