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Rev. 1.00
41 of 486
July 31, 2018
32-Bit Arm
®
Cortex
®
-M0+ MCU
HT32F50231/HT32F50241
4 Flash Memory Controller (FMC)
Option Byte Description
The Option Byte can be treated as an independent Flash memory of which base address is
0x1FF0_0000. The following table shows the function description and Option Byte memory map.
Table 6. Option Byte Memory Map
Option Byte Offset
Description
Reset Value
Option Byte Base Address = 0x1FF0_0000
OB_PP
0x000
0x004
0x008
0x00C
Flash Page Erase / Program Protection (n = 0 ~ 127)
OB_PP [n] (n = 0 ~ 62)
0: Flash Page n Erase / Program Protection is enabled
1: Flash Page n Erase / Program Protection is disabled
OB_PP [n] (n = 63 ~ 127)
Reserved
0xFFFF_FFFF
0xFFFF_FFFF
0xFFFF_FFFF
0xFFFF_FFFF
OB_CP
0x010
Flash Security Protection
OB_CP [0]
0: Flash Security protection is enabled
1: Flash Security protection is disabled
Option Byte Protection
OB_CP [1]
0: Option Byte protection is enabled
1: Option Byte protection is disabled
OB_CP [31:2]
Reserved
0xFFFF_FFFF
OB_CK
0x020
Flash Option Byte Checksum
OB_CK [31:0]
OB_CK should be set as the content value sum of 5
registers which offset address is from 0x000 to 0x010 in
Option Byte (0x000 + 0x004 + 0x008 + 0x00C + 0x010)
when the OB_PP or OB_CP register’s content is not equal
to 0xFFFF_FFFF. Otherwise, both page erase / program
protection and security protection will be enabled.
0xFFFF_FFFF