MC912DG128A Motorola, MC912DG128A Datasheet - Page 69

• Manufacturer Part Number: MC912DG128A
• Description: Microcontrollers
• Manufacturer: Motorola

1-mapping
MOTOROLA
Contents
Introduction
Internal Resource Mapping
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Internal Resource Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Flash EEPROM mapping through internal Memory Expansion . . . . . 72
Miscellaneous System Control Register . . . . . . . . . . . . . . . . . . . . . . . 77
Mapping test registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Memory Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
After reset, most system resources can be mapped to other addresses
by writing to the appropriate control registers.
The internal register block, RAM, and EEPROM have default locations
within the 64K byte standard address space but may be reassigned to
other locations during program execution by setting bits in mapping
registers INITRG, INITRM, and INITEE. During normal operating modes
these registers can be written once. It is advisable to explicitly establish
these resource locations during the initialization phase of program
execution, even if default values are chosen, in order to protect the
registers from inadvertent modification later.
Writes to the mapping registers go into effect between the cycle that
follows the write and the cycle after that. To assure that there are no
unintended operations, a write to one of these registers should be
followed with a NOP instruction.
Resource Mapping
Resource Mapping
MC68HC912DT128A Rev 2.0
Resource Mapping
69