GD32F403xx User Manual
40
Block
Name
Address Range
size
(bytes)
Page 255
0x0807 F800 - 0x0807 FFFF
2KB
Page 256
0x0808 0000 - 0x0808 0FFF
4KB
Page 257
0x0808 1000 - 0x0808 1FFF
4KB
Page 895
0x082F F000 - 0x082F FFFF
4KB
Informati
on Block
GD32F403xx
Boot loader area
0x1FFF B000- 0x1FFF F7FF
18KB
Option bytes Block
Option bytes
0x1FFF F800 - 0x1FFF F80F
16B
Note:
The Inf ormation Block stores the boot loader. This block cannot be programmed or
erased by user.
2.3.2.
Read operations
The f lash can be addressed directly as a common memory space. Any instruction fetch and
the data access from the flash are through the IBUS or DBUS from the CPU.
2.3.3.
Unlock the FMC_CTLx registers
Af ter reset, the FMC_CTLx registers are not accessible in write mode, and the LK bit in
FMC_CTLx register is 1. An unlocking sequence consists of two write operations to the
FMC_KEY0 register to open the access to the FMC_CTL0 register. The two write operations
are writing 0x45670123 and 0xCDEF89AB to the FMC_KEY0 register. Af ter the two write
operations, the LK bit in FMC_CTL0 register is reset to 0 by hardware. The software can lock
the FMC_CTL again by setting the LK bit in FMC_CTL0 register to 1. Any wrong operations
to the FMC_KEY0, set the LK bit to 1, and lock FMC_CTL0 register, and lead to a bus error.
The OBPG bit and OBER bit in FMC_CTL0 are still protected even the FMC_CTL0 is
unlocked. The unlocking sequence is two write operations, which are writing 0x45670123 and
0xCDEF89AB to FMC_OBKEY register. And then the hardware sets the OBWE N bit in
FMC_CTL0 register to 1. The software can reset OBWEN bit to 0 to protect the OBPG bit and
OBER bit in FMC_CTL0 register again.
For GD32F403xx with f lash more than 512KB, the FMC_CTL0 register is used to configure
the operations to bank0 and the option bytes block, while FMC_CTL1 register is used to
conf igure the program and erase operations to bank 1. The lock/unlock mechanism of
FMC_CTL1 register is similar to FMC_CTL0 register. The unlock sequence should be written
to FMC_KEY1 when unlocking FMC_CTL1.
Содержание GD32F403 Series
Страница 1: ...GigaDevice Semiconductor Inc GD32F403xx Arm Cortex M4 32 bit MCU User Manual Revision 2 6 Jul 2022 ...
Страница 177: ...GD32F403xx UserManual 177 Peripheral Channel 0 Channel 1 Channel 2 Channel 3 Channel 4 SDIO SDIO ...
Страница 217: ...GD32F403xx UserManual 217 ensures that no conversion is in progress ...