Fujitsu MB90390 Series Hardware Manual page 577

●
When a program error occurs:
The main body of the patch program and program address are transferred to the MCU through the
connector (UART). The MCU writes the information to E
●
Reset sequence
The MCU reads the value of E
main body of the patch program is read from E
PADR0 or PADR1 to set the patch address and sets the compare enable bit. If the relocatable patch
program is required, the first address of the patched program can be written to the RAM area. In this case,
the INT9 routine accesses this user-defined RAM area and jumps to the patched program.
●
INT9 interrupt
The interrupt routine can know the address where the interrupt occurs by checking the value of the stack
program counter. The information that has been placed on the stack during the interrupt is discarded.
■ Example of Program Patch Processing
RAM
ROM
Setting the program address detecting of reset sequence, executing normal program
Branch to the patch program that is expanded to RAM by INT9 interruption from address match detection.
Executing the patch program by branching of INT9 operation.
Executing the normal program that is branched by the patch program
2
PROM after reset. If the number of bytes of the patch program is not 0, the
Figure 26.4-2 Example of Program Patch Processing
000000
H
Correction program
Program address
detection register
Program address
detection setting
(reset sequence)
Abnormal program
FFFFFF
H
CHAPTER 26 ADDRESS MATCH DETECTION FUNCTION
2
PROM.
2
PROM and written to RAM. The MCU then uses either
Correction program byte number
Interrupt generation address
Correction program
2
E PROM
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