Features
■ Counters for seconds, minutes, hours, day, date, month, years, and century
■ 32 KHz crystal oscillator integr...
Features
■ Counters for seconds, minutes, hours, day, date, month, years, and century
■ 32 KHz crystal oscillator integrating load capacitance (12.5 pF) providing exceptional oscillator stability and high crystal series resistance operation
■ Oscillator stop detection monitors clock operation
■ Serial interface supports I2C bus (400 kHz protocol)
■ Low standby current 0.9 µA (typ at 3 V)
■ 2.0 to 5.5 V clock operating
voltage
■ Special software programmable output
■ Operating temperature of –40 to 85 °C
M41T0
Serial real-time clock
8 1
SO8
June 2011
Doc ID 9105 Rev 7
1/23
www.st.com
1
Contents
Contents
M41T0
1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1 2-wire bus characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1.1 Bus not busy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.1.2 Start data transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.1.3 Stop data transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.1.4 Data valid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.1.5 Acknowledge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...