M48T559 ST Microelectronics, M48T559 Datasheet - Page 8

• Manufacturer Part Number: M48T559
• Description: 64 Kbit 8Kb x8 TIMEKEEPER SRAM with ADDRESS/DATA MULTIPLEXED
• Manufacturer: ST Microelectronics

M48T559Y
Table 10. Register Map
Keys:
The M48T559Y may respond to transient noise
spikes on V
during the time the device is sampling V
fore, decoupling of the power supply lines is rec-
ommended.
When V
switches power to the internal battery which pre-
serves data and powers the clock. The internal
button cell will maintain data in the M48T559Y for
an accumulated period of at least 7 years when
V
and V
nected, and the power supply is switched to exter-
8/18
Address
CC
1FFDh
1FFCh
1FFFh
1FFEh
1FFBh
1FFAh
1FF9h
1FF8h
1FF7h
1FF6h
1FF5h
1FF4h
1FF3h
1FF2h
1FF1h
1FF0h
is less than V
CC
S = SIGN Bit
FT = FREQUENCY TEST Bit
R = READ Bit
W = WRITE Bit
ST = STOP Bit
0 = Must be set to zero
Y = ’1’ or ’0’
Z = ’0’ and are Read only
AF = Alarm Flag
CC
rises above V
CC
RPT4
RPT3
RPT2
RPT1
WDS
WDF
drops below V
AFE
D7
ST
W
Y
0
0
0
0
0
that reach into the deselect window
BMB4
SO
D6
AF
FT
R
Y
Y
Y
Y
0
0
0
Alarm 10 Seconds
. As system power returns
10 Years
Alarm 10 Minutes
SO
10 Seconds
10 Minutes
, the battery is discon-
SO
BMB3
ABE
Al. 10 Hours
D5
Al. 10 Date
S
Y
Z
0
0
, the control circuit
10 Hours
10 Date
BMB2
10 M
D4
BL
Y
Y
0
CC
Data
. There-
BMB1
D3
Y
Y
Z
0
Calibration
BMB0
Alarm Seconds
Alarm Minutes
Alarm Hours
D2
Alarm Date
Y
Y
Z
Seconds
Minutes
nal V
reaches V
tion on Battery Storage Life refer to the Application
Note AN1012.
POWER-ON RESET
The M48T559Y continuously monitors V
V
pulls low (open drain) and remains low on power-
up for 40ms to 200ms after V
external pull-up resistor to V
sistor is recommended). The reset pulse remains
active with V
Month
Hours
Date
CC
Year
falls to the power fail detect trip point, the RST
RB1
Day
CC
D1
BL = Battery Low
WDS = Watchdog Steering Bit
BMB0-BMB4 = Watchdog Multiplier Bits
RB0-RB1 = Watchdog Resolution Bits
AFE = Alarm Flag Enable
ABE = Alarm in Battery Back-up Mode Enable
RPT1-RPT4 = Alarm Repeat Mode Bits
WDF = Watchdog Flag
Y
Y
Z
. Write protection continues until V
PFD
CC
RB0
D0
(max) plus t
Y
Y
Z
at V
SS
Alarm Seconds
Alarm Minutes
Alarm Hours
Alarm Date
.
Watchdog
Interrupts
Seconds
Minutes
Unused
Control
Month
Flags
Date
Hour
Year
Day
REC
Function/Range
CC
BCD Format
CC
. For more informa-
is required (1k re-
passes V
00-99
01-12
01-31
01-07
00-23
00-59
00-59
01-31
00-23
00-59
00-59
CC
PFD
. When
. An
CC