Table of contents
3820 GROUP USER’S MANUAL
ii
LCD DRIVE CONTROL CIRCUIT ..............................................................................................1-32
Bias Control and Applied Voltage to LCD Power Input Pins ..................................................1-34
Common Pin and Duty Ratio Control .....................................................................................1-34
LCD Display RAM...................................................................................................................1-35
LCD Drive Timing ...................................................................................................................1-35
WATCHDOG TIMER ....................................................................................................................1-38
Initial Value of Watchdog Timer..............................................................................................1-38
Watchdog Timer Operation ....................................................................................................1-38
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CLOCK OUTPUT FUNCTION.................................................................................................1-39
RESET CIRCUIT ..........................................................................................................................1-40
CLOCK GENERATING CIRCUIT ...............................................................................................1-42
Frequency Control ..................................................................................................................1-42
Oscillation Control ..................................................................................................................1-42
NOTES ON PROGRAMMING.....................................................................................................1-45
Processor Status Register......................................................................................................1-45
Interrupt ..................................................................................................................................1-45
Decimal Calculations ..............................................................................................................1-45
Timers.....................................................................................................................................1-45
Multiplication and Division Instructions...................................................................................1-45
Ports .......................................................................................................................................1-45
Serial I/O.................................................................................................................................1-45
Instruction Execution Time .....................................................................................................1-45
DATA REQUIRED FOR MASK ORDERS ................................................................................1-46
ROM PROGRAMMIG METHOD .................................................................................................1-46
Absolute maximum ratings.......................................................................................................1-47
Recommended operating conditions ......................................................................................1-47
Electrical characteristics ...........................................................................................................1-49
Timing requirements 1 ..............................................................................................................1-51
Timing requirements 2 ..............................................................................................................1-51
Switching characteristics 1 ......................................................................................................1-52
Switching characteristics 2 ......................................................................................................1-52
Absolute maximum ratings (Extended operating temperature version) ..........................1-53
Recommended operating conditions (Extended operating temperature version) ..........................................
1-53
Electrical characteristics (Extended operating temperature version)...............................1-55
Timing requirements 1 (Extended operating temperature version)..................................1-57
Timing requirements 2 (Extended operating temperature version)..................................1-57
Switching characteristics 1 (Extended operating temperature version)..........................1-58
Switching characteristics 2 (Extended operating temperature version)..........................1-58
Absolute maximum ratings (Low power source voltage version) ...................................1-59
Recommended operating conditions (Low power source voltage version)
....................................................
1-59
Electrical characteristics (Low power source voltage version) ........................................1-61
Timing requirements 1 (Low power source voltage version)...........................................1-63
Timing requirements 2 (Low power source voltage version)...........................................1-63
Switching characteristics 1 (Low power source voltage version) ...................................1-64
Switching characteristics 2 (Low power source voltage version) ...................................1-64
Timing diagram ...........................................................................................................................1-65
STANDARD CHARACTERISTICS ..............................................................................................1-66
Power Source Current Characteristic Examples (I
CC
–V
CC
characteristics) ............................1-66
Power Source Frequency Characteristic Examples ..................................................................1-68
Port Standard Characteristic Examples......................................................................................1-69