參數(shù)資料
型號(hào): DS17887
英文描述: 3V/5V Real-Time Clock
文件頁數(shù): 9/38頁
文件大小: 410K
代理商: DS17887
DS17885/DS17887
9 of 38
CONTROL REGISTERS
The four control registers; A, B, C, and D reside in both bank 0 and bank 1. These registers are accessible
at all times, even during the update cycle.
REGISTER A
MSB
LSB
BIT 0
RS0
BIT 7
UIP
BIT 6
DV2
BIT 5
DV1
BIT 4
DV0
BIT 3
RS3
BIT 2
RS2
BIT 1
RS1
UIP – Update-in-Progress.
The UIP bit is a status flag that can be monitored. When the UIP bit is a 1,
the update transfer occurs soon. When UIP is a 0, the update transfer does not occur for at least 244μs.
The time, calendar, and alarm information in RAM is fully available for access when the UIP bit is 0. The
UIP bit is read-only. Writing the SET bit in Register B to a 1 inhibits any update transfer and clears the
UIP status bit.
DV2, DV1, DV0
– These bits are defined as follows:
DV2
= Countdown Chain
1 – Resets countdown chain only if DV1 = 1
0 – Countdown chain enabled
DV1
= Oscillator Enable
0 – Oscillator off
1 – Oscillator on, V
CC
power-up state
DV0
= Bank Select
0 – Original bank
1 – Extended registers
A pattern of 01x is the only combination of bits that turns the oscillator on and allows the RTC to keep
time. A pattern of 11x enables the oscillator but holds the countdown chain in reset. The next update
occurs at 500ms after a pattern of 01x is written to DV2, DV1, and DV0.
RS3, RS2, RS1, RS0 –
These four rate-selection bits select one of the 13 taps on the 15-stage divider or
disable the divider output. The tap selected can be used to generate an output square wave (SQW pin)
and/or a periodic interrupt. The user can do one of the following:
Enable the interrupt with the PIE bit;
Enable the SQW output pin with the SQWE or E32k bits;
Enable both at the same time and the same rate; or
Enable neither.
Table 2 lists the periodic interrupt rates and the square-wave frequencies that can be chosen with the RS
bits.
相關(guān)PDF資料
PDF描述
DS17885EN-3 3V/5V Real-Time Clock
DS17885EN-5 3V/5V Real-Time Clock
DS17885-3 3V/5V Real-Time Clock
DS17885E-3 3V/5V Real-Time Clock
DS17885E-5 3V/5V Real-Time Clock
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DS17887-3 功能描述:實(shí)時(shí)時(shí)鐘 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
DS17887-3+ 功能描述:實(shí)時(shí)時(shí)鐘 3V/5V RTC 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
DS17887-3IND 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:Real-Time Clocks
DS17887-3-IND 功能描述:實(shí)時(shí)時(shí)鐘 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
DS17887-3IND+ 功能描述:實(shí)時(shí)時(shí)鐘 3V/5V RTC 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