Z8F0830HH020SG Datasheet, PDF (136/257 Pages) Zilog, Inc. – High-Performance 8-Bit Microcontrollers

Z8 Encore!^® F0830 Series
Product Specification
118
• The Flash Sector Protect Register is ignored for programming and Erase operations.
• Programming operations are not limited to the page selected in the page select register.
• Bits in the Flash Sector Protect Register can be written to one or zero.
• The second write of the page select register to unlock the Flash Controller is not
necessary.
• The page select register can be written when the Flash Controller is unlocked.
• The mass erase command is enabled through the Flash Control Register
Caution: For security reasons, Flash Controller allows only a single page to be opened for write/
erase. When writing multiple Flash pages, the Flash Controller must go through the un-
lock sequence again to select another page.
NVDS Operational Requirements
The device uses a 12 KB Flash memory space, despite the maximum specified Flash size
of 8 KB (with the exception of 12 KB mode with non-NVDS). User code accesses the
lower 8 KB of Flash, leaving the upper 4 KB for proprietary (for Zilog-only) memory. The
NVDS is implemented by using this proprietary memory space for special-purpose rou-
tines and for the data required by these routines, which are factory-programmed and can-
not be altered by the user. The NVDS operation is described in detail in the Nonvolatile
Data Storage chapter on page 134.
The NVDS routines are triggered by a user code: CALL into proprietary memory. Code
executing from this proprietary memory must be able to read and write other locations
within proprietary memory. User code must not be able to read or write proprietary mem-
ory.
Flash Control Register Definitions
This section defines the features of the following Flash Control registers.
Flash Control Register: see page 119
Flash Status Register: see page 120
Flash Page Select Register: see page 121
Flash Sector Protect Register: see page 122
Flash Frequency High and Low Byte Registers: see page 123
PS025113-1212
NVDS Operational Requirements