M41T93 datasheet(17/51 Pages) STMICROELECTRONICS

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M41T93

Clock operation

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3.2

Clock/control register map

The M41T93 offers 32 internal registers which contain Clock, Calibration (Digital and

Analog), Alarm 1 and 2, Watchdog, Flags, Timer, and Square Wave. The Clock registers are

memory locations which contain external (user accessible) and internal copies of the data

(usually referred to as BiPORT™ TIMEKEEPER® cells). The external copies are

independent of internal functions except that they are updated periodically by the

simultaneous transfer of the incremented internal copy. The internal divider (or clock) chain

will be reset upon the completion of a WRITE to any clock address (00h to 07h). The

system-to-user transfer of clock data will be halted whenever the address being read is a

clock address (00h to 07h). The update will resume either due to a Stop Condition or when

the pointer increments to a non-clock address. Clock and Alarm Registers store data in BCD

format. Calibration, Timer, Watchdog, and Square Wave Bits are written in a Binary Format.

M41T93 Datasheet(PDF) 17 Page - STMicroelectronics