MC68HC08AS20 Datasheet, PDF (56/386 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

5.3 Functional Description
The mask options are hard-wired connections, specified at the same
time as the ROM code, which allow the user to customize the MCU. The
options control the enable or disable ability of the following functions:
• ROM security¹
• Resets caused by the LVI module
• Power to the LVI module
• Stop mode recovery time (32 CGMXCLK cycles or 4096
CGMXCLK cycles)
• COP timeout period (8,176 CGMXCLK cycles or 262,128
CGMXCLK cycles)
• STOP instruction
• Computer operating properly module (COP)
The mask option register ($001F) is used in the initialization of various
options. For error free compatibility with the emulator OTP
(M68HC708AS48CFN), a write to $001F in the MC68HC08AS20 has no
effect in MCU operation.
5.4 Mask Option Register
Address: $001F
Bit 7
6
5
4
3
2
1
Read:
R
Write:
ROMSEC LVIRSTD LVIPWRD SSREC
R
R
R
R
COPL
R
STOP
R
Reset:
Unaffected by Reset
R = Reserved
Figure 5-1. Mask Option Register (MOR)
Bit 0
COPD
R
Advance Information
56
1. No security feature is absolutely secure. However, Freescale’s strategy is to make reading or
copying the ROM data difficult for unauthorized users.
MC68HC08AS20 —Rev. 4.1
Freescale Semiconductor