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CHAPTER 3 CPU
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Features of the General-purpose Registers
The general-purpose registers have the following features:
•
High-speed access with short instructions (general-purpose register addressing)
•
Register banks (in blocks) that allow data to be easily conserved and partitioned in the unit of function
The general-purpose registers allow specific register banks to be statically assigned with the interrupt
processing routine or vector call (CALLV #0 to #7) processing routine. For example, it can be used such
that the fourth register bank is always used for the second interrupt.
For interrupts, unless data in a specific register bank that corresponds to an interrupt processing is
incorrectly overwritten by another routine, simply specifying the specific register bank at the beginning of
the interrupt processing routine stores the data contained in the general-purpose registers before
interruption. This feature allows data in general-purpose registers to avoid being put in the stack and allows
interrupts to be handled efficiently at high speed.
For subroutine calls, in addition to conservation of data in general-purpose registers, the register banks can
implement re-entrant programs (reloadable programs with variable addresses unfixed) that are usually
created using the index register (IX) or another function.
Note:
A program must be created so that the values of the interrupt level bits in the condition code register
(CCR: IL1 and IL0) do not change when the register bank pointer (RP) is rewritten to specify a register
bank in the interrupt processing routine.
Summary of Contents for F2MC-8L F202RA
Page 2: ......
Page 4: ......
Page 32: ...16 CHAPTER 1 OVERVIEW ...
Page 90: ...74 CHAPTER 3 CPU ...
Page 142: ...126 CHAPTER 5 TIME BASE TIMER POPW A RETI ENDS END ...
Page 150: ...134 CHAPTER 6 WATCHDOG TIMER ...
Page 176: ...160 CHAPTER 7 8 BIT PWM TIMER ...
Page 220: ...204 CHAPTER 8 8 16 BIT CAPTURE TIMER COUNTER ...
Page 240: ...224 CHAPTER 9 12 BIT PPG TIMER ...
Page 274: ...258 CHAPTER 11 EXTERNAL INTERRUPT CIRCUIT 2 LEVEL ...
Page 362: ...346 CHAPTER 15 BUZZER OUTPUT ...
Page 390: ...374 CHAPTER 17 FLASH MEMORY ...
Page 419: ...403 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Page 434: ...418 INDEX ...
Page 436: ......