Fujitsu CM71-00101-5E User Manual
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CHAPTER 4
RESET AND "EIT"
PROCESSING
This chapter describes reset and "EIT" processing in the
FR family CPU.
A reset is a means of forcibly terminating the currently
executing process, initializing the entire device, and
restarting the program from the beginning. "EIT"
processing, in contrast, terminates the currently
executing process and saves restart information to the
memory, then transfers control to a predetermined
processing program. "EIT" processing programs can
return to the prior program by use of the "RETI"
instruction.
"EIT" processing operates in essentially the same
manner for exceptions, interrupts and traps, with the
following minor differences.
• Interrupts originate independently of the instruction
FR family CPU.
A reset is a means of forcibly terminating the currently
executing process, initializing the entire device, and
restarting the program from the beginning. "EIT"
processing, in contrast, terminates the currently
executing process and saves restart information to the
memory, then transfers control to a predetermined
processing program. "EIT" processing programs can
return to the prior program by use of the "RETI"
instruction.
"EIT" processing operates in essentially the same
manner for exceptions, interrupts and traps, with the
following minor differences.
• Interrupts originate independently of the instruction
sequence. Processing is designed to resume from the
instruction immediately following the acceptance of
the interrupt.
instruction immediately following the acceptance of
the interrupt.
• Exceptions are related to the instruction sequence,
and processing is designed to resume from the
instruction in which the exception occurred.
instruction in which the exception occurred.
• Traps are also related to the instruction sequence,
and processing is designed to resume from the
instruction immediately following the instruction in
which the trap occurred.
instruction immediately following the instruction in
which the trap occurred.