µ
PD4990A
SERIAL I/O REAL TIME CLOCK IC
©
1996
1988
Document No. IEU-1210 (1st edition)
Date Published March 1997 P
Printed in Japan
TABLE OF CONTENTS
CHAPTER 1 INTRODUCTION ................................................................................................................. 1
1.1 FEATURE .................................................................................................................................. 1
1.2 PIN CONNECTION DIAGRAM (TOP VIEW) ........................................................................... 2
1.3 PIN FUNCTION ......................................................................................................................... 2
1.4 BLOCK DIAGRAM .................................................................................................................... 3
1.5 SHIFT REGISTER ..................................................................................................................... 4
1.6 TIME COUNTER ....................................................................................................................... 5
1.7 15 STAGES DIVIDER ............................................................................................................... 5
1.8 DATA INPUT/OUTPUT ............................................................................................................. 5
CHAPTER 2 FUNCTION SPECIFICATION ............................................................................................. 7
2.1 COMMAND SETTING ............................................................................................................... 7
2.1.1
2.1.2
2.1.3
2.2.1
2.2.2
Parallel Command Mode ............................................................................................................. 7
Serial Command Mode ................................................................................................................ 7
Caution of Command Setting ..................................................................................................... 9
Parallel Command Mode ........................................................................................................... 11
Serial Command Mode .............................................................................................................. 13
2.2 COMMAND SPECIFICATION ................................................................................................. 11
CHAPTER 3 ACCESS SEQUENCE....................................................................................................... 19
3.1 HOW TO READ DATA OF CLOCK ........................................................................................ 19
3.2 HOW TO WRITE DATA OF CLOCK ...................................................................................... 21
CHAPTER 4 EXPLANATION OF ELECTRICAL CHARACTERISTICS ............................................... 23
4.1 CRYSTAL OSCILLATOR ........................................................................................................ 23
4.2 HOW TO ADJUST OSCILLATION FREQUENCY ................................................................. 23
4.3 OSCILLATION CHARACTERISTICS ..................................................................................... 23
4.3.1
4.3.2
Temperature Characteristics .................................................................................................... 24
Supply Voltage Characteristics ................................................................................................ 25
4.4 SUPPLY CURRENT CHARACTERISTICS ............................................................................ 25
CHAPTER 5 INTERFACE ...................................................................................................................... 27
5.1 POWER SUPPLY CIRCUIT .................................................................................................... 27
5.2 POWER FAIL CIRCUIT .......................................................................................................... 30
CHAPTER 6 APPLICATION CIRCUIT & SOFTWARE ......................................................................... 33
6.1
µ
COM-75X (4 BIT SINGLE CHIP CPU) ................................................................................. 33
6.2
µ
COM-87AD (8 BIT SINGLE CHIP CPU) .............................................................................. 37
6.3 80 SERIES MULTI CHIP CPU ................................................................................................ 40
CHAPTER 7 CONVERTING
µ
PD1990A TO
µ
PD4990A ....................................................................... 43
7.1 SPECIFICATION DIFFERENCE ............................................................................................. 43
7.2 DIFFERENCE OF OSCILLATOR ........................................................................................... 44
APPENDIX
µ
PD4990A SPECIFICATION .............................................................................................. 45
–i–
LIST OF FIGURES
Figure No.
1-1
1-2
1-3
1-4
2-1
2-2
3-1
3-2
3-3
3-4
3-5
3-6
4-1
4-2
4-3
4-4
4-5
4-6
5-1
5-2
Title
Page
52 bit Shift Register ................................................................................................................................... 4
Data INPUT/OUTPUT ................................................................................................................................ 5
Data Write Action ....................................................................................................................................... 5
Data Read Action ....................................................................................................................................... 5
Parallel Command Timing (C
0
, C
1
, C
2
) ..................................................................................................... 9
Serial Command timing (C
0
’, C
1
’, C
2
’, C
3
’) .............................................................................................. 10
Read Data Flow-chart .............................................................................................................................. 19
Read Data Timing-chart (Using C
0
, C
1
, C
2
) ............................................................................................ 20
Read Data Timing-chart (Using C
0
’, C
1
’, C
2
’, C
3
’) .................................................................................. 20
Write Data Flow-chart .............................................................................................................................. 21
Write Data Timing-chart (Using C
2
, C
1
, C
0
) ............................................................................................ 22
Write Data Timing-chart (Using C
3
,’ C
2
’, C
1
’, C
0
’) ................................................................................... 22
Crystal Oscillator ...................................................................................................................................... 23
Measurement Circuit of Oscillation Characteristics ............................................................................... 23
Temperature Characteristics.................................................................................................................... 24
Temperature Characteristics (Only
µ
PD4990A) ..................................................................................... 24
Measurement Circuit ................................................................................................................................ 25
Supply Current Characteristics ............................................................................................................... 26
Application Circuit No. 1 .......................................................................................................................... 27
Application Circuit No. 2 .......................................................................................................................... 28
5-3 (a) Application Circuit (Using 74LS07) ......................................................................................................... 29
5-3 (b) Application Circuit (Using 74HC4050) .................................................................................................... 29
5-4
5-5
5-6
6-1
6-2
6-3
7-1
7-2
Power Fail Circuit ..................................................................................................................................... 30
Faulty Example ........................................................................................................................................ 30
Characteristics of Fig. 5-5 ....................................................................................................................... 31
Application Circuit for
µ
COM-75X ........................................................................................................... 33
Application Circuit for
µ
COM-87AD ........................................................................................................ 37
Application Circuit (Back Up Power Supply) .......................................................................................... 40
Oscillator of
µ
PD4990A and
µ
PD1990A ................................................................................................. 44
Oscillation Wave of
µ
PD4990A and
µ
PD1990A ..................................................................................... 44
– ii –
LIST OF TABLES
Table No.
1-1
2-1
2-2
2-3
2-4
6-1
7-1
Title
Page
48 bit Shift Register Construction ............................................................................................................. 4
Parallel Command ..................................................................................................................................... 7
Serial Command ........................................................................................................................................ 8
Timing Pulse Control Command ............................................................................................................. 13
Timing Pulse Control Command ............................................................................................................. 15
Application Software for
µ
COM-75X ....................................................................................................... 34
SPECIFICATION DIFFERENCE ............................................................................................................. 43
– iii –
LIST OF LISTS
List No.
6-2
6-3
Title
Page
Application Software for
µ
COM-87AD .................................................................................................... 38
Application Software for
µ
PD780A/
µ
PD70008A ..................................................................................... 41
– iv –
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