W79E217A Datasheet, PDF (17/207 Pages) Winbond – 8-bit Microcontroller

Preliminary W79E217A Data Sheet
Figure 6-4: NVM data memory control timing
For security purposes, this NVM data flash provides an independent “Lock bit” located in Security bits.
It is used to protect the customer’s 2K bytes of data code. It may be enabled after the external
programmer finishes the programming and verifying sequence. Once this bit is set to logic 0, the 2K
bytes of NVM Flash EPROM data can not be accessed again by external device.
Note:
1. NVMF can be polled or by h/w interrupt to indicate NVM data memory erase or write
operation has completed.
2. While user program is erasing or writing to NVM data memory, the PC counter will continue
to fetch for next instruction.
3. When uC is in idle mode and if NVM interrupt and global interrupt are enabled, the
completion of either erasing or programming the NVM data memory will exit the idle
condition.
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Publication Release Date: December 14, 2007
Revision A3.0