GD32A50x User Manual
65
SRAMCMD will be
cleared. Otherwise, wait until the command has been finished. Note that
bank 1 is used in the process and cannot be used for other operations.
Fast program SRAM
The fast program SRAM command is sent by configuring the SRAMCMD bits as "01". After
sending the fast program SRAM command, the Shared RAM initializes to all 1.
If the fast
program SRAM
is ready, the PRAMRDY bit in FMC_WS register will be set and SRAMCMD
will be
cleared. Otherwise, wait until the command has been finished. The EEPROM can not
be read or write when the Shared RAM is configured as fast program SRAM.
The reset state of Shared RAM is determined by EPLOAD in option bytes 1. If the EPLOAD
is 0, the Shared RAM will not be used for any function after system reset. Otherwise, the
Shared RAM is configured as EEPROM SRAM after system reset.
Note:
When configuring the SRAMCMD bits, it is required to check which SRAM is available
currently. The configuration cannot be repeated. For example, if it is currently basic SRAM,
the SRAMCMD should not be configured as "10" again. The current type of SRAM can be
checked by BRAMRDY / ERAMRDY / PRAMRDY bits in
FMC_WS register.
2.3.13.
Data Flash operation
The data flash size is configured by EFALC.
Read
The read of Data Flash is same as main flash. Refer to
Program
The Program is same as bank 1 program. Refer to
Page erase
The page erase is same as bank 1 page erase. Refer to
Mass erase
The mass erase is same as bank 1 mass erase. Refer to
Note:
1. The mass erase is split to page erase by hardware. The erase time is longer than
normal mass erase.
2. The mass erase command is setting MERDF bit in FMC_CTL1 register.
2.3.14.
Emulated EEPROM
The EEPROM SRAM size is configured by EPSIZE. And the EEPROM backup size is