MC68HC08AZ32A Datasheet, PDF (62/456 Pages) Motorola, Inc – HCMOS Microcontroller Unit

EEPROM
Freescale Semiconductor, Inc.
5.5.4 EEPROM Block Protection
The 512 bytes of EEPROM are divided into four 128-byte blocks. Each
of these blocks can be protected from erase/program operations by
setting the EEBPx bit in the EENVR. Table 5-1 shows the address
ranges for the blocks.
Table 5-1. EEPROM Array Address Blocks
Block Number (EEBPx)
EEBP0
EEBP1
EEBP2
EEBP3
Address Range
$0800–$087F
$0880–$08FF
$0900–$097F
$0980–$09FF
These bits are effective after a reset or a upon read of the EENVR
register. The block protect configuration can be modified by
erasing/programming the corresponding bits in the EENVR register and
then reading the EENVR register. Please see EEPROM Array
Configuration Register on page 69 for more information.
NOTE:
Once EEDIVSECD in the EEDIVHNVR is programmed to 0 and after a
system reset, the EEDIV security feature is permanently enabled
because the EEDIVSECD bit in the EEDIVH is always loaded with 0
thereafter. Once this security feature is armed, erase and program mode
are disabled for EEDIVHNVR and EEDIVLNVR. Modifications to the
EEDIVH and EEDIVL registers are also disabled. Therefore, be cautious
on programming a value into the EEDIVHNVR.
5.5.5 EEPROM Programming and Erasing
The unprogrammed or erase state of an EEPROM bit is a logic 1. The
factory default for all bytes within the EEPROM array is $FF.
The programming operation changes an EEPROM bit from logic 1 to
logic 0 (programming cannot change a bit from logic 0 to a logic 1). In a
single programming operation, the minimum EEPROM programming
size is one bit; the maximum is eight bits (one byte).
Technical Data
62
MC68HC08AZ32A — Rev 1.0
EEPROM
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