M41T93 datasheet(6/49 Pages) STMICROELECTRONICS

6 / 49 page

Summary description

M41T93

6/49

Summary description

The M41T93 is a low power Serial SPI Bus Real Time Clock with a built-in 32.768kHz

oscillator (external crystal-controlled for the QFN16 package, and embedded crystal for the

SOX18 package). Eight bytes of the Register Map (see Table 3 on page 18) are used for the

clock/calendar function and are configured in binary coded decimal (BCD) format. An

additional 17 bytes of the Register Map provide status/control of the two Alarms, Watchdog,

8-Bit Counter, and Square Wave functions. An additional seven bytes are made available as

user SRAM.

Addresses and data are transferred serially via a serial SPI bus-compatible interface. The

built-in address register is incremented automatically after each WRITE or READ data byte.

The M41T93 has a built-in power sense circuit which detects power failures and

automatically switches to the battery supply when a power failure occurs. The energy

needed to sustain the clock operations can be supplied by a small lithium button battery

when a power failure occurs.

Functions available to the user include a non-volatile, time-of-day clock/calendar, Alarm

interrupt, Watchdog Timer, programmable 8-bit Counter, and Square Wave outputs. The

eight clock address locations contain the century, year, month, date, day, hour, minute,

second, and tenths/hundredths of a second in 24 hour BCD format. Corrections for 28, 29

(leap year), 30, and 31 day months are made automatically. The M41T93 is supplied in

either a QFN16 or an SOX18 (MY), 300mil SOIC which includes an embedded 32kHz

crystal. The SOX18 package requires only a user-supplied battery to provide non-volatile

operation.

M41T93 数据表(PDF) 6 Page - STMicroelectronics