BQ4850Y_14 Datasheet, PDF (2/17 Pages) Texas Instruments – RTC Module With 512Kx8 NVSRAM

Not Recommended For New Designs
bq4850Y
Functional Description
Figure 1 is a block diagram of the bq4850Y. The follow-
ing sections describe the bq4850Y functional operation,
including memory and clock interface, and data-
retention modes.
Internal
Quartz
Crystal
Time-
Base
-.. 8
Oscillator
3
4
CE
OE
DQ₀ -DQ₇
AD ₀-AD ₁₈
WE
V_CC
Internal
Battery
Control/Status
Registers
P
Clock Alarm and
Bus
Calendar Bytes
I/F
User Buffer
(8 Bytes)
Power-
Fail
Control
Storage
Registers
(524,288 Bytes)
Write-
Protect
-.. 64
16 : 1 MUX
Clock/Calendar
Update
-.. ₆₄
BD-961
Truth Table
VCC
CE
< VCC (max.)
VIH
VIL
> VCC (min.)
VIL
VIL
< VPFD (min.) > VSO
X
≤ VSO
X
Figure 1. Block Diagram
OE
WE
Mode
DQ
Power
X
X
Deselect
High Z
Standby
X
VIL
Write
DIN
Active
VIL
VIH
Read
DOUT
Active
VIH
VIH
Read
High Z
Active
X
X
Deselect
High Z
CMOS standby
X
X
Deselect
High Z
Battery-backup mode
SLUS057A- January 2005
2