
Connectivity line devices: reset and clock control (RCC)
RM0008
134/1096
Doc ID 13902 Rev 12
8.3.3
Clock interrupt register (RCC_CIR)
Address offset: 0x08
Reset value: 0x0000 0000
Access: no wait state, word, half-word and byte access
Bits 1:0
SW[1:0]
: System clock Switch
Set and cleared by software to select SYSCLK source.
Set by hardware to force HSI selection when leaving Stop and Standby mode or in case of failure of
the HSE oscillator used directly or indirectly as system clock (if the Clock Security System is
enabled).
00: HSI selected as system clock
01: HSE selected as system clock
10: PLL selected as system clock
11: Not allowed
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Reserved
CSSC
PLL3
RDYC
PLL2
RDYC
PLL
RDYC
HSE
RDYC
HSI
RDYC
LSE
RDYC
LSI
RDYC
w
w
w
w
w
w
w
w
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Res.
PLL3
RDYIE
PLL2
RDYIE
PLL
RDYIE
HSE
RDYIE
HSI
RDYIE
LSE
RDYIE
LSI
RDYIE
CSSF
PLL3
RDYF
PLL2
RDYF
PLL
RDYF
HSE
RDYF
HSI
RDYF
LSE
RDYF
LSI
RDYF
rw
rw
rw
rw
rw
rw
rw
r
r
r
r
r
r
r
r
Bits 31:24 Reserved, always read as 0.
Bit 23
CSSC
: Clock security system interrupt clear
This bit is set by software to clear the CSSF flag.
0: No effect
1: Clear CSSF flag
Bit 22
PLL3RDYC
: PLL3 Ready Interrupt Clear
This bit is set by software to clear the PLL3RDYF flag.
0: No effect
1: Clear PLL3RDYF flag
Bit 21
PLL2RDYC
: PLL2 Ready Interrupt Clear
This bit is set by software to clear the PLL2RDYF flag.
0: No effect
1: Clear PLL2RDYF flag
Bit 20
PLLRDYC
: PLL ready interrupt clear
This bit is set by software to clear the PLLRDYF flag.
0: No effect
1: Clear PLLRDYF flag
Bit 19
HSERDYC
: HSE ready interrupt clear
This bit is set by software to clear the HSERDYF flag.
0: No effect
1: Clear HSERDYF flag