MC908KX2MDWE Datasheet, PDF (199/210 Pages) Freescale Semiconductor, Inc – High-performance M68HC08 architecture, Fully upward-compatible object code with M6805, M146805, and M68HC05 Families

Configuration Register Programming
B.2.2 Partial Use of FLASH-Related Module
16.3 Monitor ROM (MON) was written having FLASH as user memory and user vector space.
MON functions are maintained for the ROM version. MON will allow execution of code in random-access
memory (RAM) or ROM and provide ROM memory security⁽¹⁾. The memory programming interface,
though, will have no effect in ROM version.
An assumption that must be made for the ROM version is that the reset vector will always have a value
different from $0000, corresponding to the user code start address. For this reason, force entry into
monitor mode, described in 16.3.1.1 Monitor Mode Entry and in 16.3.1.3 Forced Monitor Mode, is not
applicable to the ROM version. The MENRST module has been eliminated from the ROM version.
The security function described in 16.3.2 Security also applies to the user ROM memory for the ROM
version.
B.3 Configuration Register Programming
Functionally, the terms MOR (mask option register) and CONFIG (configuration register) can be used
interchangeably. MOR and CONFIG are equivalent since both define the same module functionality
options through the registers bits. As a naming convention, though, configuration registers are named
MOR for a ROM version and CONFIG for a FLASH version.
Some modules affected by the configuration register bits make reference to default values of these bits
and have recommendation notes on programming them.
For specific information see:
• FLASH — 2.5 FLASH Memory (FLASH)
• ICG — 7.6 CONFIG (or MOR) Register Options
• LVI — 10.3 Functional Description
• PORT — 11.3.1 Port B Data Register
• COP — 5.4.7 COPD (COP Disable) and 5.4.8 COPRS (COP Rate Select)
• CONFIG — 4.2 Functional Description
NOTE
The user must keep in mind that these notes are not entirely applicable to
the MOR found in the ROM version. The MOR bits can neither assume the
described CONFIG default values after reset nor can they be modified later
under user code control. While the MOR is mask defined, and consequently
unwritable, CONFIG can be written once after each reset.
1. No security feature is absolutely secure. However, Freescale’s strategy is to make reading or copying the ROM difficult for
unauthorized users.
MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 Data Sheet, Rev. 2.1
Freescale Semiconductor
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