z8f0813 ZiLOG Semiconductor, z8f0813 Datasheet - Page 152

• Manufacturer Part Number: z8f0813
• Description: High-performance 8-bit Microcontrollers
• Manufacturer: ZiLOG Semiconductor

®
Z8 Encore! XP
F0823 Series
Product Specification
142
configurations. The information contained here is lost when page 0 of the Program
Memory is erased.
Trim Option Bits
The trim option bits are contained in the information page of the Flash memory. These bits
are factory programmed values required to optimize the operation of onboard analog cir-
cuitry and cannot be permanently altered. Program Memory may be erased without endan-
gering these values. It is possible to alter working values of these bits by accessing the
Trim Bit Address and Data Registers, but these working values are lost after a power loss
or any other reset event.
There are 32 bytes of trim data. To modify one of these values the user code must first
write a value between
and
into the Trim Bit Address Register. The next write to
00H
1FH
the Trim Bit Data register changes the working value of the target trim data byte.
Reading the trim data requires the user code to write a value between
and
into the
00H
1FH
Trim Bit Address Register. The next read from the Trim Bit Data register returns the work-
ing value of the target trim data byte.
The trim address range is from information address 20-3F only. The remainder of the
Note:
information page is not accessible through the trim bit address and data registers.
Calibration Option Bits
The calibration option bits are also contained in the information page. These bits are fac-
tory programmed values intended for use in software correcting the device’s analog per-
formance. To read these values, the user code must employ the LDC instruction to access
the information area of the address space as defined in
Flash Information Area
on page 15
Serialization Bits
®
As an optional feature, Zilog
is able to provide factory-programmed serialization. For
serialized products, the individual devices are programmed with unique serial numbers.
These serial numbers are binary values, four bytes in length. The numbers increase in size
with each device, but gaps in the serial sequence may exist.
These serial numbers are stored in the Flash information page (for more details, see
Read-
ing the Flash Information Page
on page 143 and
Serialization Data
on page 148) and are
unaffected by mass erasure of the device’s Flash memory.
Randomized Lot Identification Bits
As an optional feature, Zilog is able to provide a factory-programmed random lot
identifier. With this feature, all devices in a given production lot are programmed with the
same random number. This random number is uniquely regenerated for each successive
production lot and is not likely to be repeated.
PS024314-0308
Flash Option Bits