UPD4991ACX Renesas Electronics America, UPD4991ACX Datasheet - Page 31

• Manufacturer Part Number: UPD4991ACX
• Manufacturer: Renesas Electronics America

Specifications of UPD4991ACX

• Lead Free Status / RoHS Status: Supplier Unconfirmed

2048 Hz
"H" "L"
1 pulse
1 Hz
(3) Leap year counter (low-order 2 bits of address 0C
(4) CONTROL REGISTER 1
(5) CONTROL REGISTER 2
(6) MODE REGISTER
This counter takes a value of 0
counter is 0
in the leap year is 29.
Usually, the leap year counter is automatically set when the lower 2 digits of a year is written in the BASIC
TIME MODE. Therefore, the user does not have to write a leap year. The PD4991A operates from 1901
to 2099 without adjustment.
If a year other than a Western calender year is written to the year counter, the leap year counter may be
rewritten after the year counter has been written (if the year is Showa in the Japanese calender, for example,
divide the Showa year by 4 and add 1 to the result. Write this year to the leap year counter. Unless the year
counter is rewritten, leap years will be automatically identified after that.)
If the year is Heisei, write the year to the year counter. The leap year counter does not have to be rewritten.
This register controls the clock of the time counter in the same manner as in the BASIC TIME MODE.
This register controls output of TP1 and TP2, alarm coincidence, and the clock to the interval timer, in the same
manner as in the BASIC TIME MODE.
This register determines the operation mode of the PD4991A in the same manner as in the BASIC TIME
MODE.
Alarm
coincidence
Alarm
coincidence
Alarm
coincidence
H
30.5 s
, a leap year is identified. If the leap year identification function is enabled, the last day of February
With auto reset
Alarm
non-coinci-
dence
Alarm
coincidence
again
H
Alarm
non-coinci-
dence
Alarm
coincidence
again
Figure 2-9. TP1 Output Waveform
to 3
H
CHAPTER 2 OPERATIONS
and is synchronized with the year counter. When the value of the leap
2048 Hz
"H" "L"
1 pulse
H
)
1 Hz
Alarm
coincidence
Alarm
coincidence
Alarm
coincidence
30.5 s
Without auto reset
Alarm
non-coinci-
dence
Alarm
non-coinci-
dence
Alarm
coincidence
again
Alarm
coincidence
again
Alarm
coincidence
again
29