运行RAM没问题，烧录FLASH时失败，有以下错误提示，烧录的官网FLASH例程，同时硬件复位引脚一直高电平没有方波，GPIOF4引脚处于高电平，
C28xx: Flash Programmer: Error erasing flash memory. Device is locked or not connected. Operation cancelled
C28xx: Flash Programmer: Error erasing Flash memory.
C28xx: Flash Programmer: Device is locked or not connected. Operation cancelled.
C28xx: Trouble Writing Memory Block at 0x3f63e8 on Page 0 of Length 0x16
Cannot write to target
根据on-chip flash界面，密码都是默认的oxff
