m41t93 STMicroelectronics, m41t93 Datasheet - Page 17

• Manufacturer Part Number: m41t93
• Description: Serial Spi Bus Rtc With Battery Switchover
• Manufacturer: STMicroelectronics

M41T93
Clock operation
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.
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