DatasheetQ Logo
Electronic component search and free download site.
Transistors,MosFET ,Diode,Integrated circuits

M48T128Y View Datasheet(PDF) - STMicroelectronics

Part Name
Description
Manufacturer
M48T128Y Datasheet PDF : 22 Pages
1 2 3 4 5 6 7 8 9 10 Next Last
M48T128Y, M48T128V*
OPERATION MODES
Figure 4., page 5 illustrates the static memory ar-
ray and the quartz controlled clock oscillator. The
clock locations contain the year, month, date, day,
hour, minute, and second in 24 hour BCD format.
Corrections for 28, 29 (leap year - valid until 2100),
30, and 31 day months are made automatically.
Byte 1FFF8h is the clock control register. This byte
controls user access to the clock information and
also stores the clock calibration setting. The seven
clock bytes (1FFFFh - 1FFF8h) are not the actual
clock counters, they are memory locations consist-
ing of BiPORTâ„¢ READ/WRITE memory cells
within the static RAM array. The M48T128Y/V in-
cludes a clock control circuit which updates the
clock bytes with current information once per sec-
ond. The information can be accessed by the user
in the same manner as any other location in the
static memory array. The M48T128Y/V also has its
own Power-Fail Detect circuit. This control circuitry
constantly monitors the supply voltage for an out
of tolerance condition. When
ance, the circuit write protects
tVhCeCTIisMEouKtEoEfPtoElRer®-
Register data and external SRAM, providing data
security in the midst of unpredictable system oper-
ation. As VCC falls below the Battery Back-up
Switchover Voltage (VSO), the control circuitry au-
tomatically switches to the battery, maintaining
data and clock operation until valid power is re-
stored.
Table 2. Operating Modes
Mode
VCC
E
G
Deselect
WRITE
READ
4.5 to 5.5V
or
3.0 to 3.6V
VIH
X
VIL
X
VIL
VIL
READ
VIL
VIH
Deselect VSO to VPFD (min)(1)
X
X
Deselect
≤ VSO(1)
X
X
Note: X = VIH or VIL; VSO = Battery Back-up Switchover Voltage.
1. See Table 11., page 18 for details.
W
DQ0-DQ7
X
High Z
VIL
DIN
VIH
DOUT
VIH
High Z
X
High Z
Power
Standby
Active
Active
Active
CMOS Standby
X
High Z
Battery Back-up Mode
6/22
 

Share Link: 

datasheetq.com  [ Privacy Policy ]Request Datasheet ] [ Contact Us ]