Reserved Memory Spaces - Motorola DSP56012 User Manual

Memory, Operating Modes, and Interrupts
DSP56012 Data and Program Memory Maps
3.3.1

Reserved Memory Spaces

Certain areas of the memory maps are labelled 'reserved.' Memory spaces marked as
reserved should not be accessed by the user. They are reserved to retain
compatibility with future enhanced or derivative versions of this device. Write
operations to the reserved range are ignored. Read operations from addresses in the
reserved range return the value $000005, which is the opcode for the ILLEGAL
instruction. If an instruction fetch is attempted from an address in the reserved area,
the value returned is $000005, (ILLEGAL opcode).
Figure 3-1 Memory Maps for PEA = 0, PEB = 0
MOTOROLA DSP56012 User's Manual 3-5