GD32A50x User Manual
73
Address
Name
Description
1100: Reserved
1101: Reserved
1110: Reserved
1111: 0 Bytes
[7:4]
EFALC[3:0]
Specified the size of the data flash and EEPROM backup in the extend
flash memory. Extend
memory that is not partitioned for data flash is
used to store EEPROM records.
EFALC
Data flash size (KB)
EEPROM backup size (KB)
0010
16
0
0111
4
12
1010
0
16
1101
8
8
1110
12
4
1111
Default value. The extended flash is not configured with
a valid partition code.
Note:
1. Bits 63:32 is the complement byte of Bits 31:0. When option bytes 1 reload, if the option
complement byte and option byte does not match, the OB1ERR bit in FMC_OB1CS register
is set.
2. When the size and partition is modified, the whole extend flash will be erased by hardware.
And the endurance data will be lost.
3. If the modification of size and partition is illegal, the operation will be ignored and an error
occurs. If EPSIZE is 0 bytes (1111b), EEPROM backup size in EFALC must be 0. If EPSIZE
is not 0 bytes (1111b), EEPROM backup size in EFALC must not be 0.
4. It is recommended to configure the option bytes 1 only once throughout the life cycle. The
modification of option bytes 1 takes effect after the a system reset, or setting the OBRLD bit
in FMC_CTL1 register.
5. It is recommended to do a power reset after the modification of option bytes 1.
2.3.18.
erase / program protection
The FMC provides page erase / program protection functions to prevent inadvertent
operations on the flash memory. The page erase or program will not be accepted by the FMC
on protected pages. If the page erase or program command is sent to the FMC on a protected
page, the WPERR bit in the FMC_STATx register will then be set by the FMC. If the WPERR
bit is set and the ERRIE bit is set, then the flash operation error interrupt will be generated to
get the attention of the CPU.