Datasheet
Clock operation M41T93
20/56 DocID12615 Rev 8
Table 3. Clock/control register map (32 bytes)
Addr
Function/range BCD format
D7 D6 D5 D4 D3 D2 D1 D0
00h 0.1 seconds 0.01 seconds Seconds 00-99
01h ST 10 seconds Seconds Seconds 00-59
02h 0 10 minutes Minutes Minutes 00-59
03h CB1 CB0 10 hours Hours (24-hour format) Century/hours 0-3/00-23
04h 0 0 0 0 0 Day of week Day 01-7
05h 0 0 10 date Date: day of month Date 01-31
06h 0 0 0 10M Month Month 01-12
07h 10 Years Year Year 00-99
08h OUT FT DCS DC4 DC3 DC2 DC1 DC0 Digital calibration
09h OFIE BMB4 BMB3 BMB2 BMB1 BMB0 RB1 RB0 Watchdog
0Ah A1IE SQWE ABE Al1 10M Alarm1month Al1 month 01-12
0Bh RPT14 RPT15 AI1 10 date Alarm1 date Al1 date 01-31
0Ch RPT13 HT AI1 10 hour Alarm1 hour Al1 hour 00-23
0Dh RPT12 Alarm1 10 minutes Alarm1 minutes Al1 min 00-59
0Eh RPT11 Alarm1 10 seconds Alarm1 seconds Al1 sec 00-59
0Fh WDF AF1 AF2
(1)
1. AF2 will always read 0 if the AL2E bit is set to 0.
BL TF OF 0 0 Flags
10h Timer countdown value Timer value
11h TE
TI/TP TIE 0 0 0 TD1 TD0 Timer control
12h ACS AC6 AC5 AC4 AC3 AC2 AC1 AC0
Analog
calibration
13h RS3 RS2 RS1 RS0 0 0 AL2E OTP SQW
14h 0 0 0 Al2 10M Alarm2 month SRAM/Al2 month 01-12
15h RPT24 RPT25 AI2 10 date Alarm2 month SRAM/Al2 date 01-31
16h RPT23 0 AI2 10 hour Alarm2 date SRAM/Al2 hour 00-23
17h RPT22 Alarm2 10 minutes Alarm2 minutes SRAM/Al2 min 00-59
18h RPT21 Alarm2 10 seconds Alarm2 seconds SRAM/Al2 sec 00-59
19h-
1Fh
User SRAM (7 bytes) SRAM
0 = Must be set to zero OFIE = Oscillator fail interrupt enable
ABE = Alarm in battery backup enable bit OTP = OTP control bit
A1IE = Alarm1 interrupt enable bit RB0-RB2 = Watchdog resolution bits
AC0-AC6 = analog calibration bits RPT11-RPT15 = Alarm 1 repeat mode bits
ACS = analog calibration sign bit RPT21-RPT25 = Alarm 2 repeat mode bits
AF1, AF2 = Alarm flag RS0-RS3 = SQW frequency
AL2E = Alarm 2 enable bit SQWE = Square wave enable
BL = Battery low bit SRAM/
ALM2 = SRAM/Alarm 2 bit
BMB0-BMB4 = Watchdog multiplier bits ST = Stop bit
CB0, CB1 = Century bits TD0, TD1 = Timer frequency bits
DC0-DC4 = Digital calibration bits TE = Timer enable bit
DCS = Digital calibration sign bit TF = Timer flag
FT = Frequency test bit
TI/TP = Timer interrupt or pulse
HT = Halt update bit TIE = Timer interrupt enable
OF = Oscillator fail bit WDF = Watchdog flag
OUT= Output level