MC68HC05PV8 Datasheet, PDF (166/196 Pages) Freescale Semiconductor, Inc – Techinal Data - rev 1.9

Technical Data
Freescale Semiconductor, Inc.
14.5 Options Register
The options register (OPTR), which also contains the protect function for
the Program EEPROM in the MC68HC805PV8 version, is located at
$2000 and allows the user to select options in a non-volatile manner.
The contents of the OPTR register are loaded into data latches with each
reset.
OPTR R
$2000 W
RESET
BIT 7
NA
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
HVRE HTRE STOPR
CME
NA
NA
NA
NA
NA
Figure 14-2 Options Register
BIT 1
EEPRT
NA
BIT 0
COPD
NA
EEPRT – Program EEPROM Protect (only MC68HC805PV8)
The EEPRT bit allows the Program EEPROM ($2004–$3EFF,
$3FF0–$3FFF) to be protected. If the EEPRT bit is in the erased state
(logic 0), the EEPROM is not protected and can be used as a regular
byte erasable EEPROM. As soon as the EEPRT bit is programmed to
1, the EEPROM is hardware protected. The EEPROM can still be
read, but any attempt to erase or program will be unsuccessful. When
this bit is cleared, protection remains until the next power-on or
external reset occurs. In single chip mode, addresses $2000–$2003
are always write protected.
1 = EEPROM protected
0 = EEPROM erasable and writable
COPD – COP (Computer Operating Properly) Reset Disabled
The COPD bit allows the COP (computer operating properly timer) to
be disabled. If the COPD bit is in an erased state (logic 0), the COP
is enabled. Programming this bit (logic 1) disables the COP. Changes
to this bit do not take effect until the next power-on or external reset
occurs.
1 = COP disabled
0 = COP enabled
Technical Data
MC68HC(8)05PV8/A — Rev. 1.9
Program EEPROM
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