Electronics America 8-Bit Single-Chip Microcontrollers User's Manual

545
CHAPTER 25 ROM CORRECTION
Internal ROM
Correction place 1
Internal ROM
JUMP
Internal ROM
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
FFFFH
F7FFH
F7FDH
yyyyH
xxxxH
0000H
BR !JUMP
Destination judge program
Correction program 2
Correction program 1
Correction place 2
Figure 25-10. Program Transition Diagram (when two places are corrected)
(1) Branches to address F7FDH when fetch address matches correction address
(2) Branches to branch destination judgment program
(3) Branches to correction program 1 by branch destination judgment program (BTCLR !CORST0, $xxxxH)
(4) Returns to internal ROM program
(5) Branches to address F7FDH when fetch address matches correction address
(6) Branches to branch destination judgment program
(7) Branches to correction program 2 by branch destination judgment program (BTCLR !CORST1, $yyyyH)
(8) Returns to internal ROM program
Remark Area filled with diagonal lines : Internal expansion RAM
JUMP : Destination judge program start address