ZLF645 MAXIM [Maxim Integrated Products], ZLF645 Datasheet - Page 79

• Manufacturer Part Number: ZLF645
• Description: Flash MCUs with Learning Amplification
• Manufacturer: MAXIM [Maxim Integrated Products]

ZLF645 Series Flash MCUs
Product Specification
71
3. The CPU writes to the Page Select (PGS) register.
Figure 20
displays the basic Flash Controller operation considering code based CPU Flash
accesses and based upon the programming of the Flash Controllers Flash Control (FCTL),
Sector Protect (FSEC), and Page Select (FPS) Registers. As mentioned previously for ICP
based Flash accesses, the only modification to
Figure 20
is that the programming of the
Sector Protect (FSEC) register is ignored and the ICP has programming and erase access
does not 
to a page independent of whether it resides in a protected sector.
Figure 20
display the effects of the Flash read/write protect bits of User Option byte 1.
If either of these bits is enabled, their function takes priority over the operation description
displayed in
Figure 20
in terms of when a page erase or byte programming access is
allowed (for more details, see
Flash Code Protection Against External Access
on page 73).
19-4572; Rev 0; 4/09
Flash Controller Overview