AT32F421
Series Reference Manual
2022.11.11
Page 74
Rev 2.02
5.8.4
Flash status register (FLASH_STS)
Bit
Abbr.
Reset value
Type
Description
Bit 31: 6
Reserved
0x0000000
resd
Kept at its default value
Bit 5
ODF
0
rw1c
Operation done flag
This bit is set by hardware when Flash memory
operations (program/erase) are complete. It is
cleared by writing “1”.
Bit 4
EPPERR
0
rw1c
Erase/program protection error
This bit is set by hardware when programming the
erase/program- protected Flash memory address. It
is cleared by writing “1”.
Bit 3
Reserved
0
resd
Kept at its default value.
Bit 2
PRGMERR
0
rw1c
Programming error
When the Flash programming address is in “non-erase”
state, this bit is set by hardware. It is cleared by writing
“1”.
Bit 1
Reserved
0
resd
Kept at its default value.
Bit 0
OBF
0
ro
Operation busy flag
When this bit is set, it indicates that Flash memory
operation is in progress. It is cleared when operation is
complete.