參數(shù)資料
型號(hào): M48T86MH1E
廠商: STMICROELECTRONICS
元件分類(lèi): 時(shí)鐘/數(shù)據(jù)恢復(fù)及定時(shí)提取
英文描述: 1 TIMER(S), REAL TIME CLOCK, PDSO28
封裝: 0.330 INCH, ROHS COMPLIANT, PLASTIC, SOH-28
文件頁(yè)數(shù): 36/36頁(yè)
文件大?。?/td> 352K
代理商: M48T86MH1E
Obsolete
Product(s)
- Obsolete
Product(s)
M48T86
Operation
2
Operation
The M48T86 clock is driven by a quartz-controlled oscillator with a nominal frequency of
32,768 Hz. The devices are tested not to exceed 23 ppm (parts per million) oscillator
frequency error at 25°C, which equates to approximately ±1 minute per month. Automatic
deselection of the device ensures the data integrity is not compromised should VCC fall
below specified power-fail deselect voltage (VPFD) levels (see Figure 14 on page 27). The
automatic deselection of the device remains in effect upon power up for a period of 200ms
(max) after VCC rises above VPFD, provided that the real-time clock is running and the count-
down chain is not reset. This allows sufficient time for VCC to stabilize and gives the system
clock a wake-up period so that a valid system reset can be established.
The block diagram in Figure 4 on page 8 shows the pin connections and the major internal
functions of the M48T86.
2.1
Signal description
2.1.1
VCC, VSS
DC power is provided to the device on these pins.The M48T86 uses a 5 V VCC.
2.1.2
SQW (square wave output)
During normal operation (e.g., valid VCC), the SQW pin can output a signal from one of 13
taps. The frequency of the SQW pin can be changed by programming Register A as shown
in Table 4 on page 18. The SQW signal can be turned on and off using the SQWE bit
(Register B; Bit 3). The SQW signal is not available when VCC is less than VPFD.
2.1.3
AD0-AD7 (multiplexed bidirectional address/data bus)
The M48T86 provides a multiplexed bus in which address and data information share the
same signal path. The bus cycle consists of two stages; first the address is latched, followed
by the data. Address/Data multiplexing does not slow the access time of the M48T86,
because the bus change from address to data occurs during the internal RAM access time.
Addresses must be valid prior to the falling edge of AS (see Figure 5 on page 11), at which
time the M48T86 latches the address present on AD0-AD7. Valid WRITE data must be
present and held stable during the latter portion of the R/W pulse (see Figure 6 on page 11).
In a READ cycle, the M48T86 outputs 8 bits of data during the latter portion of the DS pulse.
The READ cycle is terminated and the bus returns to a high impedance state upon a high
transition on R/W.
2.1.4
AS (address strobe input)
A positive going pulse on the Address Strobe (AS) input serves to demultiplex the bus. The
falling edge of AS causes the address present on AD0-AD7 to be latched within the
M48T86.
相關(guān)PDF資料
PDF描述
M4T32-BR12SH1 1 TIMER(S), REAL TIME CLOCK, DSS4
M50734FP-10 8-BIT, MROM, 10 MHz, MICROCONTROLLER, PQFP72
M50734SP 8-BIT, MROM, 8 MHz, MICROCONTROLLER, PDIP64
M50930-XXXFP 8-BIT, MROM, 4.3 MHz, MICROCONTROLLER, PQFP80
M50931-XXXFP 8-BIT, MROM, 4.3 MHz, MICROCONTROLLER, PQFP80
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
M48T86MH1F 功能描述:實(shí)時(shí)時(shí)鐘 5 Volt PC Drop-In 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
M48T86MH1TR 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:5.0 V PC real-time clock
M48T86PC 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:5V PC REAL TIME CLOCK
M48T86PC1 功能描述:實(shí)時(shí)時(shí)鐘 5 Volt PC Drop-In 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
M48T86PC1 制造商:STMicroelectronics 功能描述:IC - Real Time Clock