Rom Correction Application; Storing Example To Eeprom (When One Place Is Corrected); Connecting Example With Eeprom (Using 2-Wire Serial I/O Mode) - NEC PD78052 User Manual

25.4 ROM Correction Application

(1) Store the correction address and instruction after correction (patch program) to nonvolatile memory (such as
TM
EEPROM ) 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 25-4. Storing Example to EEPROM (when one place is corrected)
00H 00
10
01H
0D
02H
02
9B
02
10
FFH
Figure 25-5. Connecting Example with EEPROM (using 2-wire serial I/O mode)
PD78058, 78058Y
540
CHAPTER 25 ROM CORRECTION
EEPROM
RA78K/0
V
DD
SCK0
SB1
P32
Source program
CSEG AT 1000H
ADD A, #2
BR !1002H
EEPROM
V
DD
SCL
SDA
CS
V
DD
CE