Z8F640x/Z8F480x/Z8F320x/Z8F240x/Z8F160x
Z8 Encore!®
150
FHSWP—Flash High Sector Write Protect
FWP—Flash Write Protect
These two Option Bits combine to provide 3 levels of Program Memory protection:
FHSWP
FWP Description
0
0
0
Programming and erasure disabled for all of Program Memory.
Programming, Page Erase, and Mass Erase via User Code is disabled. Mass
Erase is available through the On-Chip Debugger.
1
Programming and Page Erase are enabled for the High Sector of the
Program Memory only. The High Sector on the Z8F640x family device
contains 1KB to 4KB of Flash with addresses at the top of the available
Flash memory. Programming and Page Erase are disabled for the other
portions of the Program Memory. Mass erase through user code is disabled.
Mass Erase is available through the On-Chip Debugger.
0 or 1
1
Programming, Page Erase, and Mass Erase are enabled for all of Program
Memory.
Program Memory Address 0001H
Table 91. Options Bits at Program Memory Address 0001H
BITS
FIELD
RESET
R/W
7
6
5
4
3
2
1
0
Reserved
U
U
U
U
U
U
U
U
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Program Memory 0001H
ADDR
Note: U = Unchanged by Reset. R/W = Read/Write.
Reserved
These Option Bits are reserved for future use and must always be 1. This setting is the
default for unprogrammed (erased) Flash.
PS017610-0404
Option Bits
ZILOG [ ZILOG, INC. ]
