参考了pdf文档中的如下描述
关于选频。。
When the FCLKDIV register is written, the FDIVLD bit is set automatically. If the FDIVLD bit is 0, the
FCLKDIV register has not been written since the last reset. If the FCLKDIV register has not been written,
any Flash program or erase command loaded during a command write sequence will not execute and the
ACCERR bit in the FSTAT register will set.
关于写命令。。
NVM command mode uses the indexed FCCOB register to provide a command code and its relevant
parameters to the Memory Controller. The user first sets up all required FCCOB fields and then initiates
the command’s execution by writing a 1 to the CCIF bit in the FSTAT register (a 1 written by the user
clears the CCIF command completion flag to 0). When the user clears the CCIF bit in the FSTAT register
all FCCOB parameter fields are locked and cannot be changed by the user until the command completes
(as evidenced by the Memory Controller returning CCIF to 1). Some commands return information to the
FCCOB register array.
关于写命令前的注意事项。。
Before launching a command, the ACCERR and FPVIOL bits in the FSTAT register must be clear (see
Section 19.3.2.7) and the CCIF flag should be tested to determine the status of the current command write
sequence. If CCIF is 0, the previous command write sequence is still active, a new command write
sequence cannot be started, and all writes to the FCCOB register are ignored.