Z8F640x/Z8F480x/Z8F320x/Z8F240x/Z8F160x
Z8 Encore!®
144
Flash Control Register Definitions
Flash Control Register
The Flash Controller must be unlocked via the Flash Control register before programming
or erasing the Flash memory. Writing the sequence 73H8CH, sequentially, to the Flash
Control register unlocks the Flash Controller. When the Flash Controller is unlocked, writ-
ing to the Flash Control register can initiate either Page Erase or Mass Erase of the Flash
memory. Writing an invalid value or an invalid sequence returns the Flash Controller to its
locked state. The Write-only Flash Control Register shares its Register File address with
the Read-only Flash Status Register.
Table 85. Flash Control Register (FCTL)
BITS
FIELD
RESET
R/W
7
6
5
4
3
2
1
0
FCMD
FF8H
0
0
0
0
0
0
0
0
W
W
W
W
W
W
W
W
ADDR
FCMD—Flash Command
73H = First unlock command.
8CH = Second unlock command.
95H = Page erase command (must be third command in sequence to initiate Page Erase).
63H = Mass erase command (must be third command in sequence to initiate Mass Erase).
PS017610-0404
Flash Memory
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