m41t83 STMicroelectronics, m41t83 Datasheet - Page 22

• Manufacturer Part Number: m41t83
• Description: Serial I 2c Bus Rtc With Battery Switchover
• Manufacturer: STMicroelectronics

3.2
22/58
Clock/control register map
The M41T8x offers 32 internal registers which contain clock, calibration (digital and analog),
Alarm 1 and 2, Watchdog, Flags, Timer, and Square Wave (M41T83 only). The clock
registers are memory locations which contain external (user accessible) and internal copies
of the data (usually referred to as BiPORT™ TIMEKEEPER
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.
®
cells). The external copies are