ML63611 User’s Manual
Chapter 4 Interrupt (INT)
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OPTION B (D): 1.5 V (3.0 V), With regulator
circuit for LCD bias
OPTION A (C): 1.5 V (3.0 V), Without regulator
circuit for LCD bias
4.3.2 Return from an Interrupt Routine
Return from a watchdog timer interrupt routine is performed with an “RTNMI” instruction.
Return from all other interrupt routines is performed with an “RTI” instruction.
Execution of “RTI” and “RTNMI” instructions both require 1 machine cycle.
When returning from an interrupt routine, the CPU performs the following processes.
(1) The call stack pointer (SP) is decremented by 1. (SP
←
SP–1)
(2) MIE is set to “1” (when an “RTNMI” instruction is used, MIE is restored to its state prior to the interrupt).
(3) 1 is added to the call stack contents and that value is loaded into the program counter (PC)
Note:
•
While the MIE flag is “0” (interrupt disabled state), if a watchdog timer interrupt is processed and an “RTI”
instruction is executed, the MIE flag will be set to “1” and interrupts enabled.
•
Use “RTNMI” instructions to return from watchdog timer interrupts only. Use “RTI” instructions for normal
interrupts.
4.3.3 Interrupt Hold Instructions
Interrupt requests are not received after execution of interrupt hold instruction. They are received after execution
of an instruction other than interrupt hold instructions.
The interrupt hold instructions follow.
•
ROM table reference instructions
•
Stack operation instructions
•
Jump instructions
•
Conditional branch instructions
•
Call/return instructions
•
“EI” (set MIE flag) instructions, “DI” (clear MIE flag) instructions and “MSA cadr15” (start melody output)
instructions within control instructions
Note:
If interrupt hold instructions are to be used consecutively, consider that a generated interrupt will be put on hold for a
considerable amount of time before the interrupt routine begins.
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Содержание ML63611
Страница 9: ...Chapter 1 Overview...
Страница 33: ...Chapter 2 CPU and Memory Spaces...
Страница 42: ...Chapter 3 CPU Control Functions...
Страница 49: ...Chapter 4 Interrupt INT...
Страница 62: ...Chapter 5 Clock Generator Circuit OSC...
Страница 71: ...Chapter 6 Time Base Counter TBC...
Страница 75: ...Chapter 7 Timers TIMER...
Страница 99: ...Chapter 8 100 Hz Timer Counter 100HzTC...
Страница 103: ...Chapter 9 Watchdog Timer WDT...
Страница 108: ...Chapter 10 Ports INPUT I O PORT...
Страница 140: ...Chapter 11 Melody Driver MELODY...
Страница 152: ...Chapter 12 Serial Port SIO...
Страница 179: ...Chapter 13 LCD Driver LCD...
Страница 200: ...Chapter 14 Battery Low Detect Circuit BLD...
Страница 204: ...Chapter 15 Power Supply Circuit POWER...
Страница 215: ...Chapter 16 A D Converter ADC...
Страница 238: ...Appendixes...
Страница 271: ...ML63611 User s Manual First Edition May 2001 Second Edition June 2001 2001 Oki Electric Industry Co Ltd PEUL63611 02...