AT32F421
Series Reference Manual
2022.11.11
Page 303
Rev 2.02
Bit 15
Reserved
0x0
resd
Kept at its default value
Bit 14: 12 MT
0x0
ro
Minute tens
Bit 11
:
8 MU
0x0
ro
Minute units
Bit 7
Reserved
0x0
resd
Kept at its default value
Bit 6: 4
ST
0x0
ro
Second tens
Bit 3: 0
SU
0x0
ro
Second units
Note: The content of this register is valid only when the TSF is set in the ERTC_STS register. It is cleared
when TSF bit is reset.
17.4.11 ERTC time stamp date register (ERTC_TSDT)
Bit
Register
Reset value
Type
Description
Bit 31: 16 Reserved
0x0000
resd
Kept at its default value
Bit 15: 13 WK
0x0
ro
Week day
Bit 12
MT
0x0
ro
Month tens
Bit 11: 8 MU
0x0
ro
Month units
Bit 7: 6
Reserved
0x0
resd
Kept at its default value
Bit 5: 4
DT
0x0
ro
Date tens
Bit 3: 0
DU
0x0
ro
Date units
Note: The content of this register is valid only when the TSF is set in the ERTC_STS register. It is cleared
when TSF bit is reset.
17.4.12 ERTC time stamp subsecond register (ERTC_TSSBS)
Bit
Register
Reset value
Type
Description
Bit 31: 16 Reserved
0x0000
resd
Kept at its default value
Bit 15: 0 SBS
0x0000
ro
Sub-second value
Note: The content of this register is valid only when the TSF is set in the ERTC_STS register. It is cleared
when TSF bit is reset.
17.4.13 ERTC smooth calibration register (ERTC_SCAL)
Bit
Register
Reset value
Type
Description
Bit 31: 16 Reserved
0x0000
resd
Kept at its default value
Bit 15
ADD
0x0
rw
Add ERTC clock
0: No ERTC clock added
1: One ERTC_CLK is inserted every 211 ERTC_CLK
cycles
Bit 14
CAL8
0x0
rw
8-second calibration period
0: No effect
1: 8-second calibration
Bit 13
CAL16
0x0
rw
16 second calibration period
0: No effect
1: 16-second calibration
Bit 12: 9
Reserved
0x0
resd
Kept at its default value
Bit 8: 0
DEC
0x000
rw
Decrease ERTC clock
DEC out of ERTC_CLK cycles are masked during the 2
20
ERTC_CLK periods. This bit is usually used with ADD.
When the ADD is set, the actual number of ERTC_CLK is
equal to 2
20
+512-DEC during the 2
20
ERTC_CLK periods.
17.4.14 ERTC tamper configuration register (ERTC_TAMP)
Bit
Register
Reset value
Type
Description
Bit 31: 19 Reserved
0x0000
resd
Kept at its default value
Bit 18
OUTTYPE
0x0
rw
Output type
0: Open-drain output