Stereo System User Manual

3-10 DSP56012 User’s Manual MOTOROLA
Memory, Operating Modes, and Interrupts
DSP56012 Data and Program Memory Maps
ANDI #$F3,OMR ; Clear PEA/PEB bit in OMR
ANDI #$FC,MR ; Allow a delay for remapping,
; meanwhile re-enable interrupts
JMP >Next_Address ; 2-word (long) jump instruction (uninterruptable)
Note: “Next_Address” is any valid program address in the new memory
configuration (after the switch). The two-word instruction “JMP
>Next_Address” can be replaced by a sequence of an NOP followed by
a one-word “JMP <Next_Address” (jump short) instruction. In cases in
which interrupts are already disabled, the sequence would be a write to
OMR with PE modified (ORI/ANDI/MOVEC), followed by an NOP as
a delay for remapping, and then followed by a JMP >long (or another
NOP and JMP <short instead).
3.3.3 Internal I/O Memory Map
The DSP56012 on-chip peripheral modules have their registers mapped to the
addresses in the internal I/O memory range, as shown in Table 3-2.
Note: Location X:$FFFE is the Bus Control Register (BCR) for the DSP56000
core. Although labelled “Reserved” on the DSP56012, the BCR remains
active. The BCR is cleared by reset and should remain cleared (i.e., do
not write to this location) since the DSP56012 does not make use of the
BCR function.
Table 3-2 Internal I/O Memory Map
Location Register
X: $FFFF Interrupt Priority Register (IPR)
X: $FFFE Reserved
X: $FFFD PLL Control Register (PCTL)
X: $FFFC Reserved
X: $FFFB Reserved
X: $FFFA Reserved
X: $FFF9 Reserved
X: $FFF8 Reserved
X: $FFF7 GPIO Control/Data Register (GPIOR)
X: $FFF6 Reserved