• Auto refresh Mode: RAS-Only, CAS-before-RAS
(CBR), and Hidden
• Low Standby power dissipation:
– 1.8mW(max) CMOS Input Level
• Single power supply: 3.3V ± 10%
• Byte Write and Byte Read operation via two CAS
• Extended Temperature Range -30oC to 85oC
• Industrail Temperature Range -40oC to 85oC
PIN CONFIGURATION
50-Pin TSOP (Type II)
NOVEMBER 1999
DESCRIPTION
The ISSI IS41LV16400 is 4,194,304 x 16-bit high-performance CMOS Dynamic Random Access Memories.
These devices offer an accelerated cycle access called
EDO Page Mode. EDO Page Mode allows 1,024 random
accesses within a single row with access cycle time as
short as 20 ns per 16-bit word. The Byte Write control, of
upper and lower byte, makes the IS41LV16400 ideal for
use in 16-bit wide data bus systems.
These features make the S41LV16400 ideally suited for
high-bandwidth graphics, digital signal processing,
high-performance computing systems, and peripheral
applications.
The IS41LV16400 is packaged in a 50-pin TSOP (Type II).
JEDEC standard pinout.
Max. RAS Access Time (tRAC)
Max. CAS Access Time (tCAC)
Max. Column Address Access Time (tAA)
Min. EDO Page Mode Cycle Time (tPC)
Min. Read/Write Cycle Time (tRC)
Integrated Silicon Solution, Inc. — 1-800-379-4774
Rev. A
11/18/99
1
IS41LV16400ISSI
FUNCTIONAL BLOCK DIAGRAM
OE
WE
®
LCAS
UCAS
RAS
A0-A11
CAS
CLOCK
GENERATOR
RAS
CLOCK
GENERATOR
REFRESH
COUNTER
ADDRESS
BUFFERS
WE
CASWE
RAS
CONTROL
LOGICS
COLUMN DECODERS
SENSE AMPLIFIERS
ROW DECODER
OE
CONTROL
LOGIC
OE
DATA I/O BUS
I/O0-I/O15
DATA I/O BUFFERS
MEMORY ARRAY
4,194,304 x 16
2
Integrated Silicon Solution, Inc. — 1-800-379-4774
Rev. A
11/18/99
IS41LV16400ISSI
TRUTH TABLE
FunctionRASLCASUCASWEOEAddress tR/tCI/O
Standby
Read: Word
Read: Lower Byte
Read: Upper Byte
Write: Word (Early Write)
Write: Lower Byte (Early Write)
Write: Upper Byte (Early Write)
Read-Write
EDO Page-Mode Read
(1,2)
(2)
1st Cycle:
2nd Cycle:
Any Cycle:
EDO Page-Mode Write
(1)
1st Cycle:
2nd Cycle:
EDO Page-Mode
(1,2)
1st Cycle:
Read-Write2nd Cycle:
Write
(2)
(1,3)
Hidden RefreshRead
RAS-Only Refresh
CBR Refresh
Notes:
1. These WRITE cycles may also be BYTE WRITE cycles (either LCAS or UCAS active).
2. These READ cycles may also be BYTE READ cycles (either LCAS or UCAS active).
3. EARLY WRITE only.
4. At least one of the two CAS signals must be active (LCAS or UCAS).
(4)
HHHXXX
LLLHL
LLHHL
LHLHL
LLLLX
LLHLX
LHLLX
LLL
L
L
L
L
L
L
L
L→H→L
L→H→L
H→LH
H→LH
L→HL
H→LH
H→LH
H→LH
H→LH
LLHL
LLLX
→
L
→
L
→
H
→
L
→
L
→
LH
→
LH
H→LL
HL
HL
HL
LX
LX
→
→
→
H
→
LL
LL
→
H
H
LHHXX
H→L
LLXXX
ROW/COL
ROW/COL
ROW/COL
ROW/COL
ROW/COL
ROW/COL
ROW/COL
ROW/COL
NA/COL
NA/COL
ROW/COL
NA/COL
ROW/COL
NA/COL
ROW/COL
ROW/COL
ROW/NA
High-Z
DOUT
Lower Byte, DOUT
Upper Byte, High-Z
Lower Byte, High-Z
Upper Byte, DOUT
DIN
Lower Byte, DIN
Upper Byte, High-Z
Lower Byte, High-Z
Upper Byte, DIN
DOUT, DIN
DOUT
DOUT
DOUT
DIN
DIN
DOUT, DIN
DOUT, DIN
DOUT
DOUT
High-Z
High-Z
®
Integrated Silicon Solution, Inc. — 1-800-379-4774
Rev. A
11/18/99
3
IS41LV16400ISSI
®
FUNCTIONAL DESCRIPTION
The IS41LV16400 is a CMOS DRAM optimized for
high-speed bandwidth, low power applications. During
READ or WRITE cycles, each bit is uniquely addressed
through the 22 address bits: 12 row address bits (A0~A11)
and 10 column address bits (A0~A9). The row address is
latched by the Row Address Strobe (RAS). The column
address is latched by the Column Address Strobe (CAS).RAS is used to latch the first twelve bits and CAS is used
the latter ten bits.
The IS41LV16400 has two CAS controls, LCAS and
UCAS. The LCAS and UCAS inputs internally generates
a CAS signal functioning in an identical manner to the
single CAS input on the other 4M x 16 DRAMs. The key
difference is that each CAS controls its corresponding
I/O tristate logic (in conjunction with OE and WE and
RAS). LCAS controls I/O0 through I/O7 and UCAS
controls I/O8 through I/O15.
The IS41LV16400 CAS function is determined by the first
CAS (LCAS or UCAS) transitioning LOW and the last
transitioning back HIGH. The two CAS controls give the
IS41LV16400 both BYTE READ and BYTE WRITE cycle
capabilities.
Memory Cycle
A memory cycle is initiated by bring RAS LOW and it is
terminated by returning both RAS and CAS HIGH. To
ensures proper device operation and data integrity any
memory cycle, once initiated, must not be ended or
aborted before the minimum tRAS time has expired. A new
cycle must not be initiated until the minimum precharge
time tRP, tCP has elapsed.
Read Cycle
A read cycle is initiated by the falling edge of CAS or OE,
whichever occurs last, while holding WE HIGH. The
column address must be held for a minimum time
specified by tAR. Data Out becomes valid only when tRAC,
tAA, tCAC and tOEA are all satisfied. As a result, the access
time is dependent on the timing relationships between
these parameters.
Write Cycle
A write cycle is initiated by the falling edge of CAS and
WE, whichever occurs last. The input data must be valid
at or before the falling edge of CAS or WE, whichever
occurs last.
Refresh Cycle
To retain data, 4,096 refresh cycles are required in each
64 ms period. There are two ways to refresh the memory.
1. By clocking each of the 4,096 row addresses (A0
through A11) with RAS at least once every 64 ms. Any
read, write, read-modify-write or RAS-only cycle
refreshes the addressed row.
2. Using a CAS-before-RAS refresh cycle. CAS-before-RAS
refresh is activated by the falling edge of RAS, while
holding CAS LOW. In CAS-before-RAS refresh cycle,
an internal 12-bit counter provides the row addresses
and the external address inputs are ignored.
CAS-before-RAS is a refresh-only mode and no data
access or device selection is allowed. Thus, the output
remains in the High-Z state during the cycle.
Extended Data Out Page Mode
EDO page mode operation permits all 1,024 columns
within a selected row to be randomly accessed at a high
data rate.
In EDO page mode read cycle, the data-out is held to the
next CAS cycle’s falling edge, instead of the rising edge.
For this reason, the valid data output time in EDO page
mode is extended compared with the fast page mode. In
the fast page mode, the valid data output time becomes
shorter as the CAS cycle time becomes shorter. Therefore, in EDO page mode, the timing margin in read cycle
is larger than that of the fast page mode even if the CAS
cycle time becomes shorter.
In EDO page mode, due to the extended data function, the
CAS cycle time can be shorter than in the fast page mode
if the timing margin is the same.
The EDO page mode allows both read and write
operations during one RAS cycle, but the performance is
equivalent to that of the fast page mode in that case.
Power-On
After application of the VCC supply, an initial pause of
200 µs is required followed by a minimum of eight
initialization cycles (any combination of cycles containing
a RAS signal).
During power-on, it is recommended that RAS track with
VCC or be held at a valid VIH to avoid current surges.
4
Integrated Silicon Solution, Inc. — 1-800-379-4774
Rev. A
11/18/99
IS41LV16400ISSI
®
ABSOLUTE MAXIMUM RATINGS
(1)
SymbolParametersRatingUnit
VTVoltage on Any Pin Relative to GND–0.5 to +4.6V
VCCSupply Voltage–0.5 to +4.6V
IOUTOutput Current50mA
PDPower Dissipation1W
TACommercial Operation Temperature0 to +70°C
Extended Temperature–30 to +85°C
Industrail Temperature–40 to +85°C
TSTGStorage Temperature–55 to +125°C
Note:
1. Stress greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause permanent
damage to the device. This is a stress rating only and functional operation of the device at these or
any other conditions above those indicated in the operational sections of this specification is not
implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability.
RECOMMENDED OPERATING CONDITIONS (Voltages are referenced to GND.)
1. An initial pause of 200 µs is required after power-up followed by eight RAS refresh cycles (RAS-Only or CBR) before proper device
operation is assured. The eight RAS cycles wake-up should be repeated any time the tREF refresh requirement is exceeded.
2. Dependent on cycle rates.
3. Specified values are obtained with minimum cycle time and the output open.
4. Column-address is changed once each EDO page cycle.