
DocID024597 Rev 5
219/1830
RM0351
Reset and clock control (RCC)
278
6.4 RCC
registers
6.4.1 Clock
control
register (RCC_CR)
Address offset: 0x00
Reset value: 0x0000 0063. HSEBYP is not affected by reset.
Access: no wait state, word, half-word and byte access
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Res.
Res.
PLL
SAI2
RDY
PLL
SAI2
ON
PLL
SAI1
RDY
PLL
SAI1
ON
PLL
RDY
PLLON
Res.
Res.
Res.
Res.
CSS
ON
HSE
BYP
HSE
RDY
HSE
ON
r
rw
r
rw
r
rw
rs
rw
r
rw
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Res.
Res.
Res.
Res.
HSI
ASFS
HSI
RDY
HSI
KERON
HSION
MSIRANGE[3:0]
MSI
RGSEL
MSI
PLLEN
MSI
RDY
MSION
rw
r
rw
rw
rw
rw
rw
rw
rs
rw
r
rw
Bits 31:30 Reserved, must be kept at reset value.
Bit 29
PLLSAI2RDY
: SAI2 PLL clock ready flag
Set by hardware to indicate that the PLLSAI2 is locked.
0: PLLSAI2 unlocked
1: PLLSAI2 locked
Bit 28
PLLSAI2ON
: SAI2 PLL enable
Set and cleared by software to enable PLLSAI2.
Cleared by hardware when entering Stop, Standby or Shutdown mode.
0: PLLSAI2 OFF
1: PLLSAI2 ON
Bit 27
PLLSAI1RDY
: SAI1 PLL clock ready flag
Set by hardware to indicate that the PLLSAI1 is locked.
0: PLLSAI1 unlocked
1: PLLSAI1 locked
Bit 26
PLLSAI1ON
: SAI1 PLL enable
Set and cleared by software to enable PLLSAI1.
Cleared by hardware when entering Stop, Standby or Shutdown mode.
0: PLLSAI1 OFF
1: PLLSAI1 ON
Bit 25
PLLRDY
: Main PLL clock ready flag
Set by hardware to indicate that the main PLL is locked.
0: PLL unlocked
1: PLL locked
Bit 24
PLLON
: Main PLL enable
Set and cleared by software to enable the main PLL.
Cleared by hardware when entering Stop, Standby or Shutdown mode. This bit cannot be
reset if the PLL clock is used as the system clock.
0: PLL OFF
1: PLL ON