DS1553P Maxim Integrated Products, DS1553P Datasheet - Page 3

• Manufacturer Part Number: DS1553P
• Description: 64K NV Y2KC Real Time Clocks RAM
• Manufacturer: Maxim Integrated Products

DS1553 BLOCK DIAGRAM Figure 1
DS1553 OPERATING MODES Table 1
DATA READ MODE
The DS1553 is in the read mode whenever
device architecture allows ripple-through access to any valid address location. Valid data will be available
at the DQ pins within t
satisfied. If
access (t
controlled by
intermediate state until t
will remain valid for output data hold time (t
access.
DATA WRITE MODE
The DS1553 is in the write mode whenever
referenced to the latter occurring transition of
the cycle.
read or write cycle. Data in must be valid t
afterward. In a typical application, the
active provided that care is taken with the data bus to avoid bus contention. If
transitioning low, the data bus can become active with read data defined by the address inputs. A low
transition on
V
SO
V
< V
CC
<V
V
CEA
> V
CC
BAT
CC
CE
) or at output enable access time (t
CE
<V
PF
WE
and
CE
PF
or
will then disable the outputs t
WE
and
OE
V
V
V
V
CE
X
X
AA
IH
access times are not met, valid data will be available at the latter of chip enable
IL
IL
IL
must return inactive for a minimum of t
AA
OE
after the last address input is stable, providing that
. If the address inputs are changed while
. If the outputs are activated before t
V
V
OE
X
X
X
X
IH
IL
WE
V
V
V
X
X
X
IH
IH
IL
OE
DQ0-DQ7
signal will be high during a write cycle. However,
HIGH-Z
HIGH-Z
HIGH-Z
HIGH-Z
CE
D
WE
D
DS
OUT
WEZ
OH)
WE
IN
(chip enable) is low and
prior to the end of the write and remain valid for t
OEA
and
but will then go indeterminate until the next address
after
or
). The state of the data input/output pins (DQ) is
3 of 19
CE
CE
RETENTION
DESELECT
DESELECT
WE
. The addresses must be held valid throughout
are in their active state. The start of a write is
MODE
WRITE
READ
READ
DATA
goes active.
WR
prior to the initiation of a subsequent
CE
AA
, the data lines are driven to an
and
CMOS STANDBY
WE
OE
STANDBY
CURRENT
BATTERY
CE
POWER
ACTIVE
ACTIVE
ACTIVE
(write enable) is high. The
remain valid, output data
and
OE
OE
is low prior to
access times are
OE
DS1553
can be
WE
DH