Z8 Encore! XP® 4K Series
Product Specification
148
Flash Option Bits
Overview
Programmable Flash option bits allow user configuration of certain aspects of Z8 Encore!
XP® 4K Series operation. The feature configuration data is stored in the Flash program
memory and loaded into holding registers during Reset. The features available for control
through the Flash Option Bits are:
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Watch-dog timer time-out response selection–interrupt or system reset
Watch-dog timer Always on (enabled at Reset)
The ability to prevent unwanted read access to user code in Program Memory
The ability to prevent accidental programming and erasure of all or a portion of the user
code in Program Memory
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Voltage brown-out configuration-always enabled or disabled during STOP mode to re-
duce STOP mode power consumption
Oscillator mode selection-for high, medium, and low power crystal oscillators, or external
RC oscillator
Factory trimming information for the internal precision oscillator and low voltage detec-
tion
Factory calibration values for ADC, temperature sensor, and Watch-dog timer compensa-
tion
Factory serialization and randomized lot identifier (optional)
Operation
Option Bit Configuration By Reset
Each time the Flash Option Bits are programmed or erased, the device must be Reset for
the change to take effect. During any reset operation (System Reset, Power On Reset, or
STOP Mode Recovery), the Flash Option Bits are automatically read from the Flash Pro-
gram Memory and written to Option Configuration registers. The Option Configuration
registers control operation of the devices within the Z8 Encore! XP® 4K Series. Option Bit
control is established before the device exits Reset and the eZ8 CPU begins code execu-
tion. The Option Configuration registers are not part of the Register File and are not acces-
sible for read or write access.
PS022815-0206
Flash Option Bits
ZILOG [ ZILOG, INC. ]
