MO SEL VITELIC
V53C16258H
The Self Refresh mode is terminated by returning
Power-On
the RAS clock to a high level for a specified (t
)
After application of the V
supply, an initial
RPS
CC
minimum time. After termination of the Self Refresh
cycle normal accesses to the device may be initiat-
ed immediately, providing that subsequent refresh
cycles utilize the CAS before RAS (CBR) mode of
operation.
pause of 200 µs is required followed by a minimum
of 8 initialization cycles (any combination of cycles
containing a RAS clock). Eight initialization cycles
are required after extended periods of bias without
clocks (greater than the Refresh Interval).
During Power-On, the V current requirement of
CC
the V53C16258H is dependent on the input levels of
RAS and CAS. If RAS is low during Power-On, the
Data Output Operation
The V53C16258H Input/Output is controlled by
OE, CAS, WE and RAS. A RAS low transition
enables the transfer of data to and from the selected
row address in the Memory Array. A RAS high
transition disables data transfer and latches the
output data if the output is enabled. After a memory
cycle is initiated with a RAS low transition, a CAS
low transition or CAS low level enables the internal
I/O path. A CAS high transition or a CAS high level
disables the I/O path and the output driver if it is
enabled. A CAS low transition while RAS is high has
no effect on the I/O data path or on the output
drivers. The output drivers, when otherwise
enabled, can be disabled by holding OE high. The
OE signal has no effect on any data stored in the
output latches. A WE low level can also disable the
output drivers when CAS is low. During a Write
cycle, if WE goes low at a time in relationship to
CAS that would normally cause the outputs to be
active, it is necessary to use OE to disable the
output drivers prior to the WE low transition to allow
device will go into an active cycle and I will exhibit
CC
current transients. It is recommended that RAS and
CAS track with V or be held at a valid V during
CC
IH
Power-On to avoid current surges.
Table 1. V53C16258H Data Output
Operation for Various Cycle Types
Cycle Type
I/O State
Read Cycles
Data from Addressed
Memory Cell
CAS-Controlled Write
Cycle (Early Write)
High-Z
WE-Controlled Write
Cycle (Late Write)
OE Controlled. High
OE = High-Z I/Os
Read-Modify-Write
Cycles
Data from Addressed
Memory Cell
EDO Read Cycle
Data from Addressed
Memory Cell
Data In Setup Time (t ) to be satisfied.
EDO Write Cycle
(Early Write)
High-Z
DS
EDO Read-Modify-
Write Cycle
Data from Addressed
Memory Cell
RAS-only Refresh
High-Z
CAS-before-RAS
Refresh Cycle
Data remains as in
previous cycle
CAS-only Cycles
High-Z
V53C16258H Rev. 3.8 November 1999
17
MOSEL [ MOSEL VITELIC, CORP ]
