NEC uPD78P078 - Manual (Page 562)

562
CHAPTER 26 ROM CORRECTION
V
DD V
DD
V
DD
PD78078, 78078Y Subseries EEPROM
SCK0
SB1
P32
SCL
SDA
CS
CE
µ
RA78K/0
EEPROM Source program
00
10
0D
02
9B
02
10
00H
01H
02H
FFH
CSEG AT 1000H
ADD A, #2
BR !1002H
26.4 ROM Correction Application
(1) Store the correction address and instruction after correction (patch program) to nonvolatile memory (such
as EEPROM TM ) outside the microcontroller.
When two places should be corrected, store the branch destination judgment program as well. The branch
destination judgment program checks which one of the addresses set to CORAD0 or CORAD1 generates
the correction branch.
Figure 26-4. Storing Example to EEPROM (when One Place is Corrected)
Figure 26-5. Connecting Example with EEPROM (Using 2-Wire Serial I/O Mode)