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CHAPTER 22 ROM CORRECTION
User’s Manual U15798EJ2V0UD
22.5 ROM Correction Example
An example of ROM correction when the instruction at address 1000H “ADD A, #1” is changed to “ADD A, #2”
is as follows.
Figure 22-7. ROM Correction Example
(1) Branches to address F7FDH when the preset value 1000H in correction address register 0, 1 (CORAD0,
CORAD1) matches the fetch address value after the main program is started.
(2) Branches to any address (address F702H in this example) by setting the entire-space branch instruction (BR
!addr16) to address F7FDH in the main program.
(3) Returns to the internal ROM (on-chip flash memory) program after executing the substitute instruction ADD
A, #2.
ADD A, #2
BR
!1002H
BR
!F702H
ADD A, #1
MOV B, A
0000H
0080H
Program start
1000H
1002H
Internal ROM or
on-chip flash memory
Internal Expansion RAM
F400H
F702H
F7FDH
F7FFH
(1)
(2)
(3)
EFFFH
Содержание mPD780344 Series
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