參數(shù)資料
型號(hào): M48T512V-70PM1
廠商: STMICROELECTRONICS
元件分類: 時(shí)鐘/數(shù)據(jù)恢復(fù)及定時(shí)提取
英文描述: REAL TIME CLOCK, PDIP32
封裝: ROHS COMPLIANT, PLASTIC, DIP-32
文件頁(yè)數(shù): 3/23頁(yè)
文件大小: 370K
代理商: M48T512V-70PM1
M48T512Y, M48T512V
Clock operations
Doc ID 5747 Rev 6
3
Clock operations
3.1
Reading the clock
Updates to the TIMEKEEPER registers should be halted before clock data is read to
prevent reading data in transition (see Table 5 on page 12). The BiPORT TIMEKEEPER
cells in the RAM array are only data registers and not the actual clock counters, so updating
the registers can be halted without disturbing the clock itself.
Updating is halted when a '1' is written to the READ bit, D6 in the control register (7FFF8h).
As long as a '1' remains in that position, updating is halted. After a halt is issued, the
registers reflect the count; that is, the day, date, and time that were current at the moment
the halt command was issued. All of the TIMEKEEPER registers are updated
simultaneously. A halt will not interrupt an update in progress. The next update occurs 1
second after the READ bit is reset to a '0.'
3.2
Setting the clock
Bit D7 of the control register (7FFF8h) is the WRITE bit. Setting the WRITE bit to a '1,' like
the READ bit, halts updates to the TIMEKEEPER registers. The user can then load them
with the correct day, date, and time data in 24 hour BCD format (see Table 5 on page 12).
Resetting the WRITE bit to a '0' then transfers the values of all time registers 7FFFFh-
7FFF9h to the actual TIMEKEEPER counters and allows normal operation to resume. After
the WRITE bit is reset, the next clock update will occur approximately one second later.
Note:
Upon power-up, both the WRITE bit and the READ bit will be reset to '0.'
3.3
Stopping and starting the oscillator.
The oscillator may be stopped at any time. If the device is going to spend a significant
amount of time on the shelf, the oscillator can be turned off to minimize current drain on the
battery. The STOP bit is located at bit D7 within 7FFF9h. Setting it to a '1' stops the
oscillator. The M48T512Y/V is shipped from STMicroelectronics with the STOP bit set to a
'1.' When reset to a '0,' the M48T512Y/V oscillator starts after approximately one second.
Note:
It is not necessary to set the WRITE bit when setting or resetting the FREQUENCY TEST
bit (FT) or the STOP bit (ST).
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
M48T512V-85PM1 功能描述:實(shí)時(shí)時(shí)鐘 4 MBIT 512 Kbitx8 TIMEKEEPER RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 總線接口:I2C 日期格式:DW:DM:M:Y 時(shí)間格式:HH:MM:SS RTC 存儲(chǔ)容量:64 B 電源電壓-最大:5.5 V 電源電壓-最小:1.8 V 最大工作溫度:+ 85 C 最小工作溫度: 安裝風(fēng)格:Through Hole 封裝 / 箱體:PDIP-8 封裝:Tube
M48T512VPM 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:3.3V-5V 4 Mbit 512Kb x8 TIMEKEEPER SRAM
M48T512Y 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:3.3V-5V 4 Mbit 512Kb x8 TIMEKEEPER SRAM
M48T512Y_10 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:5.0 or 3.3 V, 4 Mbit (512 Kbit x 8) TIMEKEEPER? SRAM
M48T512Y-70PM1 功能描述:實(shí)時(shí)時(shí)鐘 4M (512Kx8) 70ns RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 總線接口:I2C 日期格式:DW:DM:M:Y 時(shí)間格式:HH:MM:SS RTC 存儲(chǔ)容量:64 B 電源電壓-最大:5.5 V 電源電壓-最小:1.8 V 最大工作溫度:+ 85 C 最小工作溫度: 安裝風(fēng)格:Through Hole 封裝 / 箱體:PDIP-8 封裝:Tube