参数资料
型号: RV5C339
厂商: Ricoh Co., Ltd.
英文描述: 3-WIRE SERIAL INTERFACE REAL-TIME CLOCK ICs WITH VOLTAGE MONITORING FUNCTION
中文描述: 3线串行接口实时时钟IC,带有电压检测功能
文件页数: 21/51页
文件大小: 421K
代理商: RV5C339
25
RV5C339A
Actual time
CE
Time counts within real-time clocks
13:59:59
14:00:00
14:00:01
13:59:59
14:00:00
14:00:01
MAX.61
s
1.5 Considerations in Reading and Writing Time Data
Any carry to the second digits in the process of reading or writing time data may cause reading or writing erroneous
time data. For example, suppose a carry out of 13:59:59 into 14:00:00 occurs in the process of reading time data in
the middle of shifting from the minute digits to the hour digits. At this moment, the second digits, the minute digits,
and the hour digits read 59 seconds, 59 minutes, and 14 hours, respectively (indicating 14:59:59) to cause the
reading of time data deviating from actual time virtually 1 hour. A similar error also occurs in writing time data. To
prevent such errors in reading and writing time data, the RV5C339A has the function of temporarily locking any
carry of the time digits during the high interval of the CE pin and unlocking such a carry in its high to low transition.
Note that a carry of the second digits can be locked for only 1 second, during which time the CE pin should be
driven low.
The effective use of this function requires the following considerations in reading and writing time data:
(1) Hold the CE pin high in each session of reading or writing time data.
(2) Ensure that the high interval of the CE pin lasts within 1 second. Should there be any possibility of the host
going down in the process of reading or writing time data, make arrangements in the peripheral circuitry as to
drive the CE pin low or open at the moment that the host actually goes down.
(3) Leave a time span of 31s or more from the low to high transition of the CE pin to the start of access to address-
es 0h to 6h in order that any ongoing carry of the time digits may be completed within this time span.
(4) Leave a time span of 61s or more from the high to low transition of the CE pin to its low to high transition in
order that any ongoing carry of the time digits during the high interval of the CE pin may be adjusted within this
time span.
(5) The considerations listed in (1), (3), and (4) above are not required when the process of reading or writing time
data is obviously free from any carry of the time digits (e.g. reading or writing time data in synchronization with
the periodic interrupt function in the level mode or the alarm interrupt function).
Good and bad examples of reading and writing time data are illustrated on the next page.
相关PDF资料
PDF描述
RV5VG1XXC-E1 POWER SUPPLY SUPPORT CKT, PDSO8
RX-4045NBAA REAL TIME CLOCK, PDSO22
RX-4045SA-0 REAL TIME CLOCK, PDSO14
RX-4045SA-3 REAL TIME CLOCK, PDSO14
RX-4801JE REAL TIME CLOCK, PDSO20
相关代理商/技术参数
参数描述
RV5C339A 制造商:RICOH 制造商全称:RICOH electronics devices division 功能描述:3-WIRE SERIAL INTERFACE REAL-TIME CLOCK ICs WITH VOLTAGE MONITORING FUNCTION
RV5C339A_03 制造商:RICOH 制造商全称:RICOH electronics devices division 功能描述:3-WIRE SERIAL INTERFACE REAL-TIME CLOCK IC WITH VOLTAGE MONITORING FUNCTION
RV5C339A-E2 制造商:RICOH 制造商全称:RICOH electronics devices division 功能描述:3-WIRE SERIAL INTERFACE REAL-TIME CLOCK ICs WITH VOLTAGE MONITORING FUNCTION
RV5C348A 制造商:RICOH 制造商全称:RICOH electronics devices division 功能描述:4-WIRE SERIAL INTERFACE REAL-TIME CLOCK ICs WITH VOLTAGE MONITORING FUNCTION
RV5C348B 制造商:RICOH 制造商全称:RICOH electronics devices division 功能描述:4-WIRE SERIAL INTERFACE REAL-TIME CLOCK ICs WITH VOLTAGE MONITORING FUNCTION