m41st87w STMicroelectronics, m41st87w Datasheet - Page 25

• Manufacturer Part Number: m41st87w
• Description: 5.0, 3.3, Or 3.0v, 1280 Bit 160 X8 Secure Serial Rtc And Nvram Supervisor With Tamper Detection
• Manufacturer: STMicroelectronics

Table 7. TIMEKEEPER
Keys: 0 = Must be set to zero
16h-1Dh
1Eh-1Fh
20h-9Fh
Addr
0Ch
0Dh
00h
01h
02h
03h
04h
05h
06h
07h
08h
09h
0Ah
0Bh
0Eh
0Fh
10h
11h
12h
13h
14h
15h
32kE = 32kHz Output Enable Bit
ABE = Alarm in Battery Back-Up Mode Enable Bit
AF = Alarm flag (Read only)
AFE = Alarm Flag Enable Bit
BL = Battery Low Flag (Read only)
BMB0-BMB4 = Watchdog Multiplier Bits
CB0-CB1 = Century Bits
CLR (1 and 2) = RAM Clear Bits
CLR (1 and 2)
CLRPW0 = RAM Clear Pulse Width 0 Bit
CLRPW1 = RAM Clear Pulse Width 1 Bit
FT = Frequency Test Bit
HT = Halt Update Bit
OF = Oscillator Fail Bit
OFIE = Oscillator Fail Interrupt Enable Bit
OUT = Output level
PFOD = Power-fail Output Open Drain Bit
PFOD
RPT4
RPT3
RPT2
RPT1
TEB1
TEB2
OFIE
WDS
WDF
OUT
CB1
AFE
RS3
TR
D7
ST
0
0
0
0
EXT
= RAM Clear External Bits
SQWE
BMB4
RPT5
TIE1
TIE2
CB0
THS
RS2
HT
D6
FT
AF
0
0
0
0
0
0.1 Seconds
®
10 Years
Alarm 10 Seconds
Alarm 10 Minutes
Register Map
10 Seconds
10 Minutes
CLRPW1 CLRPW0
BMB3
TCM1
TCM2
ABE
RS1
D5
S
0
0
0
0
0
AI 10 Hour
AI 10 Date
10 Hours
10 Date
Al 10M
BMB2
TPM1
TPM2
10M
RS0
D4
BL
0
0
0
Reserved
ROM
Data
SQWOD
BMB1
TDS1
TDS2
32kE
D3
0
0
0
0
Hours (24 Hour Format)
Calibration
Date: Day of Month
TCLO1
TCLO2
RB0-RB1 = Watchdog Resolution Bits
RPT1-RPT5 = Alarm Repeat Mode Bits
RS0-RS3 = SQW Frequency
S = Sign Bit
SQWE = Square Wave Enable
SQWOD = Square Wave Open Drain Bit
ST = Stop Bit
TB (1 and 2) = Tamper Bits (Read only)
TCHI/TCLO (1 and 2) = Tamper Current Hi/Tamper Current
Low Bits
TCM (1 and 2) = Tamper Connect Mode Bits
TDS (1 and 2) = Tamper Detect Sampling Bits
TEB (1 and 2) = Tamper Enable Bits
THS = Threshold Bit
TIE (1 and 2) = Tamper Interrupt Enable Bits
TPM (1 and 2) = Tamper Polarity Mode Bits
TR = t
WDS = Watchdog Steering Bit
WDF = Watchdog flag (Read only)
BMB0
TCHI/
TCHI/
Alarm Seconds
Alarm Minutes
0.01 Seconds
OF
D2
Alarm Month
Alarm Date
Alarm Hour
0
0
0
0
Seconds
Minutes
Month
rec
Year
Day of Week
Bit
CLR1
CLR2
RB1
TB1
D1
0
0
0
0
EXT
EXT
M41ST87Y, M41ST87W
CLR1
CLR2
RB0
TB2
D0
0
0
0
0
Watchdog
Reserved
Reserved
Reserved
10s/100s
128 User
Seconds
Seconds
Al Month
Tamper1
Tamper2
Century/
Function/Range
Number
Minutes
Al Date
Al Hour
Control
Month
Al Min
Al Sec
Hours
Serial
Bytes
SQW
Flags
Date
Year
BCD Format
Day
8-Byte
2-Byte
00-99
00-59
00-59
00-23
01-31
01-12
00-99
01-12
01-31
00-23
00-59
00-59
01-7
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