
RTC - 62421 / 62423
CONTENTS
! Overview....................................................................................................................... 1
! Block diagram ............................................................................................................. 1
! Pin connections.......................................................................................................... 1
! Pin functions................................................................................................................ 2
! Characteristics............................................................................................................ 3
1. Absolute maximum ratings ..............................................................................................................3
2. Operating conditions .........................................................................................................................3
3. Frequency characteristics and current consumption characteristics .................................3
4. Electrical characteristics (DC characteristics)...........................................................................3
! Switching characteristics (AC characteristics) ........................................................ 4
1. When ALE is used .............................................................................................................................4
2. When ALE is fixed at VDD ...............................................................................................................5
! Registers....................................................................................................................... 6
1. Register table.......................................................................................................................................6
2. Notes ......................................................................................................................................................6
3. Functions of register bits (overview) ............................................................................................7
4. Setting the fixed-period pulse output mode and interrupt mode .........................................7
5. Resetting the fixed-period pulse output mode and interrupt mode ....................................7
! Register description.................................................................................................. 8
1. Timing registers ..................................................................................................................................8
2. CD register (control register D) ......................................................................................................9
3. CE register (control register E).....................................................................................................10
4. CF register (control register F) .....................................................................................................12
! Using the RTC-62421 /RTC-62423 .................................................................. 13
1. Power-on procedure (initialization) .............................................................................................13
2. Read /write of S1 to W registers .................................................................................................14
3. Write to 30-second ADJ bit ...........................................................................................................15
4. Switch over between 24- and 12-hour clock modes .............................................................16
5. Using the CS1 pin ............................................................................................................................16
! Power supply circuit example ............................................................................. 17
! Examples of connection to general-purpose microprocessor................. 17
1.
Connection to multiplexed bus type .................................................................................................17
2.
Connection to Z80 or compatible CPU.............................................................................................17
3.
Connection to 68-series MPU ..........................................................................................................17
! External dimensions ............................................................................................... 18
! Marking layout .......................................................................................................... 18
! Reference data......................................................................................................... 19
(1) Example of frequency and temperature characteristics
...................................................................................19
(2) Frequency voltage characteristics (typical)
....................................................................................................19
(3) Current consumption voltage characteristics (typical)
......................................................................................19
! Application notes ..................................................................................................... 20
1. Notes on handling ............................................................................................................................20
2. Notes on packaging.........................................................................................................................20