Overview - Oki ML63611 User Manual

3. CPU Control Functions
3.1

Overview

Operating states, including system reset, are classified as follows.
•
Normal operation mode
•
System reset mode
•
Halt mode
Figure 3-1 shows the CPU operating state transition diagram.
Normal operation
The normal operation mode is the state in which the CPU executes instructions sequentially.
The system reset mode begins when a reset input causes the CPU to begin system reset processing where registers
and pins are initialized. The CPU remains in this state until instruction execution begins. After system reset
processing, instruction execution begins from address 0000H.
The halt mode is the state in which the CPU is halted (instruction execution suspended) but internal peripheral
functions continue to operate. During the halt mode, the PC is not incremented. Even upon entering the halt mode,
port and peripheral functions will not change. Transfer to the halt mode is accomplished by executing a "HALT"
instruction.
OPTION A (C): 1.5 V (3.0 V), Without regulator
circuit for LCD bias
HALT instruction execution
mode
Interrupt generated
RESET = "H"
System reset mode
RESET = "L"
Figure 3-1 Operating State Transition Diagram
Chapter 3 CPU Control Functions
Halt mode
RESET = "H"
Simultaneous key depression
at Port 0
Low-speed clock
oscillation halt detect
3 – 1
OPTION B (D): 1.5 V (3.0 V), With regulator
ML63611 User's Manual
circuit for LCD bias