Nations Technologies Inc.
Tel
:
+86-755-86309900
:
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
9
/
631
Table 2-3 Flash bus address list
Memory area
Page name
Address range
Size
Main memory area
Page 0
0x0800_0000 – 0x0800_07FF
2KB
Page 1
0x0800_0800 – 0x0800_0FFF
2KB
Page 2
0x0800_1000 – 0x0800_17FF
2KB
...
...
...
Page 63
0x0801_F800 – 0x0801_FFFF
2KB
Information area
System memory area
0x1FFF_0000 – 0x1FFF_3FFF
16KB
System configuration area
0x1FFF_F000 – 0x1FFF_F7FF
2KB
Option byte area
0x1FFF_F800 – 0x1FFF_F813
20B
Memory area
interface
register
FLASH_AC
0x4002_2000 – 0x4002_2003
4B
FLASH_KEY
0x4002_2004 – 0x4002_2007
4B
FLASH_OPTKEY
0x4002_2008 – 0x4002_200B
4B
FLASH_STS
0x4002_200C – 0x4002_200F
4B
FLASH_CTRL
0x4002_2010 – 0x4002_2013
4B
FLASH_ADD
0x4002_2014 – 0x4002_2017
4B
FLASH_OB2
0x4002_2018 – 0x4002_201B
4B
FLASH_OB
0x4002_201C – 0x4002_201F
4B
FLASH_WRP
0x4002_2020 – 0x4002_2023
4B
FLASH_ECC
0x4002_2024 – 0x4002_2027
4B
Reserved
0x4002_2028 – 0x4002_202F
8B
FLASH_CAHR
0x4002_2030 – 0x4002_2033
4B
Flash memory is organized into 32-bit wide memory units, which can store codes and data constants.
Information is divided into three parts:
The system memory area is used for storing a boot program for boot loader mode of the system memory. The
boot program uses USART1 and USB (DFU) serial interface to program the flash memory.
System configuration area, which contains basic information of the chip.
Option byte area, writing to main memory and information block is managed by embedded flash
programming/erasing controller.
There are two ways to protect flash memory from illegal access (read, write and erase):
Page write protection (WRP)
Read protection (RDP)
When the flash memory write operation is executed, any read operation to the flash memory will lock the bus, and
the read operation can only be carried out correctly after the write operation is completed. That is, when writing or
erasing, cannot have any read access to the code or data.
The internal RC oscillator (HSI) must be turned on when the flash memory is programmed (written or erased).