SAMSUNG KM718V887

KM718V887
256Kx18 Synchronous SRAM
Document Title
256Kx18-Bit Synchronous Burst SRAM
Revision History
History
Draft Date
Remark
0.0
Initial draft
May. 15. 1997
Preliminary
0.1
Modify power down cycle timing & Interleaved read timing,
Insert Note 4 at AC timing characteristics.
Change ISB1 value from 10mA to 30mA.
Change ISB2 value from 10mA to 20mA.
February. 11. 1998
Preliminary
0.2
Change Undershoot spec
from -3.0V(pulse width≤20ns) to -2.0V(pulse width≤tCYC/2)
Add Overshoot spec 4.6V((pulse width≤tCYC/2)
Change VIH max from 5.5V to VDD+0.5V
April. 14. 1998
Preliminary
0.3
May 13. 1998
Change ISB2 value from 20mA to 30mA.
Change VDD condition from VDD=3.3V+10%/-5% to VDD=3.3V+0.3V/-0.165V.
1.0
Final spec Release
May 15. 1998
Final
2.0
Add VDDQ Supply voltage( 2.5V )
Dec. 02. 1998
Final
Rev. No.
Preliminary
The attached data sheets are prepared and approved by SAMSUNG Electronics. SAMSUNG Electronics CO., LTD. reserve the right to change the
specifications. SAMSUNG Electronics will evaluate and reply to your requests and questions on the parameters of this device. If you have any questions, please contact the SAMSUNG branch office near your office, call or contact Headquarters.
-1-
December 1998
Rev. 2.0
KM718V887
256Kx18 Synchronous SRAM
256Kx18-Bit Synchronous Burst SRAM
FEATURES
GENERAL DESCRIPTION
• Synchronous Operation.
• On-Chip Address Counter.
• Write Self-Timed Cycle.
• On-Chip Address and Control Registers.
• VDD= 3.3V+0.3V/-0.165V Power Supply.
• VDDQ Supply Voltage 3.3V+0.3V/-0.165V for 3.3V I/O
The KM718V887 is a 4,718,592 bit Synchronous Static Random Access Memory designed for support zero wait state performance for advanced Pentium/Power PC address pipelining.
And with CS1 high, ADSP is blocked to control signal.
It is organized as 256K words of 18 bits and integrates address
and control registers, a 2-bit burst address counter and high
output drive circuitry onto a single integrated circuit for reduced
components count implementation of high performance cache
RAM applications.
Write cycles are internally self-timed and synchronous.
The self-timed write feature eliminates complex off chip write
pulse shaping logic, simplifying the cache design and further
reducing the component count.
Burst cycle can be initiated with either the address status processor(ADSP) or address status cache controller(ADSC)
inputs. Subsequent burst addresses are generated internally in
the system′s burst sequence and are controlled by the burst
address advance(ADV) input. ZZ pin controls Power Down
State and reduces Stand-by current regardless of CLK.
The KM718V887 is implemented in SAMSUNG′s high performance CMOS technology and is available in a 100pin TQFP
package. Multiple power and ground pins are utilized to minimize ground bounce.
or 2.5V+0.4V/-0.125V for 2.5V I/O.
• 5V Tolerant Inputs except I/O Pins.
• Byte Writable Function.
• Global Write Enable Controls a full bus-width write.
• Power Down State via ZZ Signal.
• Asynchronous Output Enable Control.
• ADSP, ADSC, ADV Burst Control Pins.
• LBO Pin allows a choice of either a interleaved burst or a
linear burst.
• Three Chip Enables for simple depth expansion with No Data
Contention.
• TTL-Level Three-State Output.
• 100-TQFP-1420A
FAST ACCESS TIMES
PARAMETER
Cycle Time
Symbol
-7
-8
-9
Unit
tCYC
8.5
10
12
ns
Clock Access Time
tCD
7.5
8
9
ns
Output Enable Access Time
tOE
3.5
3.5
3.5
ns
LOGIC BLOCK DIAGRAM
CLK
LBO
BURST CONTROL
256Kx18
MEMORY
ARRAY
A′0~A′1
A0 ~ A1
A0~A17
ADSP
ADDRESS
REGISTER
A2~A17
DATA-IN
REGISTER
CONTROL
REGISTER
CS1
CS2
CS2
GW
BW
WEa
BURST
ADDRESS
COUNTER
LOGIC
CONTROL
REGISTER
ADV
ADSC
OUTPUT
BUFFER
CONTROL
LOGIC
WEb
OE
ZZ
DQa0 ~ DQb7
DQPa, DQPb
-2-
December 1998
Rev. 2.0
KM718V887
256Kx18 Synchronous SRAM
A6
A7
CS1
CS2
N.C.
N.C.
WEb
WEa
CS2
VDD
VSS
CLK
GW
BW
OE
ADSC
ADSP
ADV
A8
A9
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
100 Pin TQFP
47
48
49
50
A14
A15
A16
A17
41
VDD
46
40
VSS
A13
39
N.C.
45
38
N.C.
A12
37
A0
44
36
A1
A11
35
A2
43
34
A3
N.C.
33
A4
42
32
N.C.
31
(20mm x 14mm)
A5
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
LBO
N.C.
N.C.
N.C.
VDDQ
VSSQ
N.C.
N.C.
DQb0
DQb1
VSSQ
VDDQ
DQb2
DQb3
N.C.
VDD
N.C.
VSS
DQb4
DQb5
VDDQ
VSSQ
DQb6
DQb7
DQPb
N.C.
VSSQ
VDDQ
N.C.
N.C.
N.C.
100
PIN CONFIGURATION(TOP VIEW)
80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
64
63
62
61
60
59
58
57
56
55
54
53
52
51
A10
N.C.
N.C.
VDDQ
VSSQ
N.C.
DQPa
DQa7
DQa6
VSSQ
VDDQ
DQa5
DQa4
VSS
N.C.
VDD
ZZ
DQa3
DQa2
VDDQ
VSSQ
DQa1
DQa0
N.C.
N.C.
VSSQ
VDDQ
N.C.
N.C.
N.C.
PIN NAME
SYMBOL
PIN NAME
A0 - A17
Address Inputs
ADV
ADSP
ADSC
CLK
CS1
CS2
CS2
WEx
OE
GW
BW
ZZ
LBO
Burst Address Advance
Address Status Processor
Address Status Controller
Clock
Chip Select
Chip Select
Chip Select
Byte Write Inputs
Output Enable
Global Write Enable
Byte Write Enable
Power Down Input
Burst Mode Control
TQFP PIN NO.
32,33,34,35,36,37,
44,45,46,47,48,49,
50,80,81,82,99,100
83
84
85
89
98
97
92
93,94
86
88
87
64
31
SYMBOL
PIN NAME
VDD
VSS
N.C.
Power Supply(+3.3V)
Ground
No Connect
DQa0~a7
DQb0~b7
DQPa, Pb
VDDQ
Data Inputs/Outputs
VSSQ
-3-
Output Power Supply
(2.5V or 3.3V)
Output Ground
TQFP PIN NO.
15,41,65,91
17,40,67,90
1,2,3,6,7,14,16,25,28,
29,30,38,39,42,43,51
52,53,56,57,66,75
78,79,95,96
58,59,62,63,68,69,72,73
8,9,12,13,18,19,22,23
74,24
4,11,20,27,54,61,70,77
5,10,21,26,55,60,71,76
December 1998
Rev. 2.0
KM718V887
256Kx18 Synchronous SRAM
FUNCTION DESCRIPTION
The KM718V887 is a synchronous SRAM designed to support the burst address accessing sequence of the Pentium and Power PC
based microprocessor. All inputs(with the exception of OE, LBO and ZZ) are sampled on rising clock edges.
The start and duration of the burst access is controlled by ADSP, ADSC, ADV and Chip Select pins.
When ZZ is pulled HIGH, the SRAM will enter a Power Down State. At this time, internal state of the SRAM is preserved. When ZZ
returns to low, the SRAM normally operates after 2cycles of wake up time. ZZ pin is pulled down internally.
Read cycles are initiated with ADSP(or ADSC) using the new external address clocked into the on-chip address register when both
GW and BW are high or when BW is low and both WEa and WEb are high, When ADSP is sampled low, the chip selects are sampled
active, and the output buffer is enabled with OE, the data of cell array accessed by the current address are projected to the output
pins.
Write cycles are also initiated with ADSP(or ADSC)and are differentiated into two kinds of operations; All byte write operation and
individual byte write operation. All byte write occurs by enabling GW(in dependent of BW and WEx.), and individual byte write is performed only when GW is High and BW is Low. WEa controls DQa0 ~ DQa7 and DQPa, WEb controls DQb0 ~ DQb7 and DQPb.
CS1 is used to enable the device and conditions internal use of ADSP and is sampled only when a new external address is loaded.
ADV is ignored at the clock edge when ADSP is asserted, but can be sampled on the subsequent clock edges. The address
increases internally for the next access of the burst when ADV is sampled low.
Addresses are generated for the burst access as shown below, The starting point of the burst sequence is provided by the external
address. The burst address counter wraps around to its initial state upon completion. The burst sequence is determined by the state
of the LBO pin. When this pin is low, linear burst sequence is selected. And when this pin is High, Interleaved burst sequence is
selected.
BURST SEQUENCE TABLE
LBO PIN
(Interleaved Burst)
Case 1
HIGH
A1
0
0
1
1
First Address
Fourth Address
Case 2
A0
0
1
0
1
A1
0
0
1
1
Case 3
A0
1
0
1
0
A1
1
1
0
0
Case 4
A0
0
1
0
1
A1
1
1
0
0
SEQUENCE TABLE
LBO PIN
A0
1
0
1
0
(Linear Burst)
Case 1
LOW
A1
0
0
1
1
First Address
Fourth Address
Case 2
A0
0
1
0
1
A1
0
1
1
0
Case 3
A0
1
0
1
0
A1
1
1
0
0
Case 4
A0
0
1
0
1
A1
1
0
0
1
A0
1
0
1
0
Note : 1. LBO pin must be tied to High or Low, and Floating State must not be allowed.
TRUTH TABLES
ASYNCHRONOUS TRUTH TABLE
(See Notes 1 and 2):
OPERATION
ZZ
OE
I/O STATUS
Sleep Mode
H
X
High-Z
L
L
DQ
Read
L
H
High-Z
Write
L
X
Din, High-Z
Deselected
L
X
High-Z
Notes
1. X means "Don′t Care".
2. ZZ pin is pulled down internally
3. For write cycles that following read cycles, the output buffers must be
disabled with OE, otherwise data bus contention will occur.
4. Sleep Mode means power down state of which stand-by current does
not depend on cycle time.
5. Deselected means power down state of which stand-by current
depends on cycle time.
-4-
December 1998
Rev. 2.0
KM718V887
256Kx18 Synchronous SRAM
SYNCHRONOUS TRUTH TABLE
CS1
CS2
CS2
H
X
X
ADSP ADSC
X
ADV
WRITE
CLK
ADDRESS ACCESSED
OPERATION
X
X
↑
None
Not Selected
None
Not Selected
L
L
L
X
L
X
X
X
↑
L
X
H
L
X
X
X
↑
None
Not Selected
L
L
X
X
L
X
X
↑
None
Not Selected
L
X
H
X
L
X
X
↑
None
Not Selected
L
H
L
L
X
X
X
↑
External Address
Begin Burst Read Cycle
L
H
L
H
L
X
L
↑
External Address
Begin Burst Write Cycle
L
H
L
H
L
X
H
↑
External Address
Begin Burst Read Cycle
X
X
X
H
H
L
H
↑
Next Address
Continue Burst Read Cycle
H
X
X
X
H
L
H
↑
Next Address
Continue Burst Read Cycle
X
X
X
H
H
L
L
↑
Next Address
Continue Burst Write Cycle
H
X
X
X
H
L
L
↑
Next Address
Continue Burst Write Cycle
X
X
X
H
H
H
H
↑
Current Address
Suspend Burst Read Cycle
H
X
X
X
H
H
H
↑
Current Address
Suspend Burst Read Cycle
X
X
X
H
H
H
L
↑
Current Address
Suspend Burst Write Cycle
H
X
X
X
H
H
L
↑
Current Address
Suspend Burst Write Cycle
Notes : 1. X means "Don′t Care".
2. The rising edge of clock is symbolized by ↑.
3. WRITE = L means Write operation in WRITE TRUTH TABLE.
WRITE = H means Read operation in WRITE TRUTH TABLE.
4. Operation finally depends on status of asynchronous input pins(ZZ and OE).
WRITE TRUTH TABLE
GW
BW
WEa
WEb
OPERATION
H
H
X
X
READ
H
L
H
H
READ
H
L
L
H
WRITE BYTE a
H
L
H
L
WRITE BYTE b
H
L
L
L
WRITE ALL BYTEs
L
X
X
X
WRITE ALL BYTEs
Notes : 1. X means "Don′t Care".
2. All inputs in this table must meet setup and hold time around the rising edge of CLK(↑).
-5-
December 1998
Rev. 2.0
KM718V887
256Kx18 Synchronous SRAM
ABSOLUTE MAXIMUM RATINGS*
PARAMETER
SYMBOL
RATING
UNIT
Voltage on VDD Supply Relative to VSS
VDD
-0.3 to 4.6
V
Voltage on VDDQ Supply Relative to VSS
VDDQ
VDD
V
Voltage on Input Pin Relative to VSS
VIN
-0.3 to 6.0
V
Voltage on I/O Pin Relative to VSS
VIO
-0.3 to VDDQ+0.5
V
Power Dissipation
PD
1.2
W
Storage Temperature
TSTG
-65 to 150
°C
Operating Temperature
TOPR
0 to 70
°C
Storage Temperature Range Under Bias
TBIAS
-10 to 85
°C
*Note : Stresses 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 operating sections of this specification is not
implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability.
OPERATING CONDITIONS at 3.3V I/O (0°C≤ TA≤70°C)
PARAMETER
Supply Voltage
Ground
SYMBOL
MIN
Typ.
MAX
UNIT
VDD
3.135
3.3
3.6
V
VDDQ
3.135
3.3
3.6
V
VSS
0
0
0
V
Typ.
MAX
OPERATING CONDITIONS at 2.5V I/O(0°C ≤ TA ≤ 70°C)
PARAMETER
Supply Voltage
Ground
SYMBOL
MIN
UNIT
VDD
3.135
3.3
3.6
V
VDDQ
2.375
2.5
2.9
V
VSS
0
0
0
V
TEST CONDI-
MIN
MAX
UNIT
CIN
VIN=0V
-
5
pF
COUT
VOUT=0V
-
8
pF
CAPACITANCE*(TA=25°C, f=1MHz)
PARAMETER
Input Capacitance
Output Capacitance
SYMBOL
*Note : Sampled not 100% tested.
-6-
December 1998
Rev. 2.0
KM718V887
256Kx18 Synchronous SRAM
DC ELECTRICAL CHARACTERISTICS(TA=0 to 70°C, VDD=3.3V+0.3V/-0.165V)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
MAX
UNIT
Input Leakage Current(except ZZ)
IIL
VDD=Max ; VIN=VSS to VDD
-2
2
µA
Output Leakage Current
IOL
Output Disabled, VOUT=VSS to VDDQ
-2
2
µA
Operating Current
ICC
Device Selected, IOUT=0mA,
ZZ≤VIL, All Inputs=VIL or VIH
Cycle Time ≥ tCYC Min
ISB
Device deselected, IOUT=0mA,
ZZ≤VIL, f=Max,
All Inputs≤0.2V or ≥ VDD-0.2V
-7
-
350
-8
-
325
-9
-
300
-7
-
100
-8
-
90
-9
-
80
ISB1
Device deselected, IOUT=0mA, ZZ≤0.2V,
f=0, All Inputs=fixed (VDD-0.2V or 0.2V)
ISB2
Device deselected, IOUT=0mA,
ZZ≥VDD-0.2V, f=Max,
All Inputs≤VIL or ≥VIH
Output Low Voltage(3.3V I/O)
VOL
IOL = 8.0mA
Output High Voltage(3.3V I/O)
VOH
IOH = -4.0mA
Output Low Voltage(2.5V I/O)
VOL
IOL = 1.0mA
Output High Voltage(2.5V I/O)
VOH
IOH = -1.0mA
Standby Current
-
mA
mA
30
mA
30
mA
-
0.4
V
2.4
-
V
-
0.4
V
2.0
-
V
-
Input Low Voltage(3.3V I/O)
VIL
-0.5*
0.8
V
Input High Voltage(3.3V I/O)
VIH
2.0
VDD+0.5**
V
Input Low Voltage(2.5V I/O)
VIL
-0.3*
0.7
V
Input High Voltage(2.5V I/O)
VIH
1.7
VDD+0.5**
V
* VIL(Min)=-2.0(Pulse Width ≤ tCYC/2)
** VIH(Max)=4.6(Pulse Width ≤ tCYC/2)
** In Case of I/O Pins, the Max. VIH=VDDQ+0.5V
TEST CONDITIONS
(VDD=3.3V+0.3V/-0.165V,VDDQ=3.3V+0.3/-0.165V or VDD=3.3V+0.3V/-0.165V,VDDQ=2.5V+0.4V/-0.125V, TA=0 to 70°C)
PARAMETER
VALUE
Input Pulse Level(for 3.3V I/O)
0 to 3V
Input Pulse Level(for 2.5V I/O)
0 to 2.5V
Input Rise and Fall Time(Measured at 0.3V and 2.7V for 3.3V I/O)
2ns
Input Rise and Fall Time(Measured at 0.3V and 2.1V for 2.5V I/O)
2ns
Input and Output Timing Reference Levels for 3.3V I/O
1.5V
Input and Output Timing Reference Levels for 2.5V I/O
VDDQ/2
Output Load
See Fig. 1
-7-
December 1998
Rev. 2.0
KM718V887
256Kx18 Synchronous SRAM
Output Load(A)
Dout
Output Load(B)
(for tLZC, tLZOE, tHZOE & tHZC)
+3.3V for 3.3V I/O
/+2.5V for 2.5V I/O
RL=50Ω
Z0=50Ω
VL=1.5V for 3.3V I/O
VDDQ/2 for 2.5V I/O
30pF*
319Ω / 1667Ω
Dout
353Ω / 1538Ω
5pF*
* Including Scope and Jig Capacitance
* Capacitive Load consists of all components of
the test environment.
Fig. 1
AC TIMING CHARACTERISTICS(TA=0 to 70°C, VDD=3.3V+0.3V/-0.165V)
PARAMETER
SYMBOL
KM718V887-7
KM718V887-8
KM718V887-9
MIN
MAX
MIN
MAX
MIN
MAX
UNIT
Cycle Time
tCYC
8.5
-
10
-
12
-
ns
Clock Access Time
tCD
-
7.5
-
8
-
9
ns
Output Enable to Data Valid
tOE
-
3.5
-
3.5
-
3.5
ns
Clock High to Output Low-Z
tLZC
0
-
0
-
0
-
ns
Output Hold from Clock High
tOH
2
-
2
-
2
-
ns
Output Enable Low to Output Low-Z
tLZOE
0
-
0
-
0
-
ns
Output Enable High to Output High-Z
tHZOE
-
3.5
-
3.5
-
3.5
ns
Clock High to Output High-Z
tHZC
2
3.5
2
3.5
2
3.5
ns
Clock High Pulse Width
tCH
3
-
4
-
4.5
-
ns
Clock Low Pulse Width
tCL
3
-
4
-
4.5
-
ns
Address Setup to Clock High
tAS
2.0
-
2.0
-
2.0
-
ns
Address Status Setup to Clock High
tSS
2.0
-
2.0
-
2.0
-
ns
Data Setup to Clock High
tDS
2.0
-
2.0
-
2.0
-
ns
Write Setup to Clock High(GW, BW, WEx)
tWS
2.0
-
2.0
-
2.0
-
ns
Address Advance Setup to Clock High
tADVS
2.0
-
2.0
-
2.0
-
ns
Chip Select Setup to Clock High
tCSS
2.0
-
2.0
-
2.0
-
ns
Address Hold from Clock High
tAH
0.5
-
0.5
-
0.5
-
ns
Address Status Hold from Clock High
tSH
0.5
-
0.5
-
0.5
-
ns
Data Hold from Clock High
tDH
0.5
-
0.5
-
0.5
-
ns
Write Hold from Clock High(GW, BW, WEx)
tWH
0.5
-
0.5
-
0.5
-
ns
Address Advance Hold from Clock High
tADVH
0.5
-
0.5
-
0.5
-
ns
Chip Select Hold from Clock High
tCSH
0.5
-
0.5
-
0.5
-
ns
ZZ High to Power Down
tPDS
2
-
2
-
2
-
cycle
ZZ Low to Power Up
tPUS
2
-
2
-
2
-
cycle
Notes : 1. All address inputs must meet the specified setup and hold times for all rising clock edges whenever ADSC and/or ADSP is sampled low and
CS is sampled low. All other synchronous inputs must meet the specified setup and hold times whenever this device is chip selected.
2. Both chip selects must be active whenever ADSC or ADSP is sampled low in order for the this device to remain enabled.
3. ADSC or ADSP must not be asserted for at least 2 Clock after leaving ZZ state.
4. At any given voltage and temperature, tHZC is less than tLZC.
-8-
December 1998
Rev. 2.0
-9-
Data Out
OE
ADV
CS
WRITE
ADDRESS
ADSC
ADSP
CLOCK
tCSS
tAS
tSS
tOE
Q1-1
tHZOE
tADVH
tWH
tSS
A2
tSH
Q2-1
tCD
tOH
Q2-2
Q2-3
A3
Q2-4
(ADV INSERTS WAIT STATE)
BURST CONTINUED WITH
NEW BASE ADDRESS
tCYC
tCL
NOTES : WRITE = L means GW = L, or GW = H, BW = L, WEx.= L
CS = L means CS1 = L, CS2 = H and CS2 = L
CS = H means CS1 = H, or CS1 = L and CS2 = H, or CS1 = L, and CS2 = L
tADVS
tCSH
tWS
tLZOE
A1
tAH
tSH
tCH
TIMING WAVEFORM OF READ CYCLE
Q3-1
Q3-2
Q3-3
Undefined
Don′t Care
Q3-4
tHZC
KM718V887
256Kx18 Synchronous SRAM
December 1998
Rev. 2.0
- 10
Data Out
Data In
OE
ADV
CS
WRITE
ADDRESS
ADSC
ADSP
CLOCK
Q0-3
tCSS
tAS
tSS
Q0-4
A1
tLZOE
tCSH
tAH
tSH
D1-1
tCH
tCYC
tCL
A2
D2-1
D2-2
(ADV SUSPENDS BURST)
D2-2
D2-3
(ADSC EXTENDED BURST)
TIMING WAVEFORM OF WRTE CYCLE
D2-4
D3-1
A3
tDS
tADVS
tWS
tSS
D3-2
tDH
tADVH
tWH
tSH
D3-3
Undefined
Don′t Care
D3-4
KM718V887
256Kx18 Synchronous SRAM
December 1998
Rev. 2.0
- 11
Data Out
Data In
OE
ADV
CS
WRITE
ADDRESS
ADSP
CLOCK
tHZC
tSS
A1
tLZC
tCD
tSH
Q1-1
tHZOE
tAS
A2
tCL
tCYC
tDS
tADVS
tWS
tAH
tCH
D2-1
tDH
tADVH
tWH
A3
tLZOE
tOE
Q3-1
Q3-2
Q3-3
tOH
Q3-4
TIMING WAVEFORM OF COMBINATION READ/WRTE CYCLE(ADSP CONTROLLED, ADSC=HIGH)
Undefined
Don′t Care
KM718V887
256Kx18 Synchronous SRAM
December 1998
Rev. 2.0
- 12
Data In
Data Out
OE
ADV
CS
WRITE
ADDRESS
ADSC
CLOCK
tCSS
tSS
A1
tLZOE
tOE
tCSH
tSH
Q1-1
A2
Q2-1
A3
Q3-1
A4
Q4-1
tHZOE
D5-1
A5
tDS
tWS
D6-1
A6
tDH
tWH
D7-1
A7
tWS
tCD
A8
A9
Q8-1
tCL
tCYC
tWH
tCH
TIMING WAVEFORM OF SINGLE READ/WRITE CYCLE(ADSC CONTROLLED, ADSP=HIGH)
December 1998
Rev. 2.0
Undefined
Don′t Care
Q9-1
tOH
KM718V887
256Kx18 Synchronous SRAM
- 13
Data In
Data Out
OE
ADV
CS
WRITE
ADDRESS
ADSP
CLOCK
tCSS
tSS
tOE
tCSH
tLZOE
A1
tSH
Q1-1
A2
Q2-1
A3
tAS
Q3-1
A4
tAH
tCYC
tCH
A5
Q4-1
tCL
tHZOE
D5-1
A6
tDS
D6-1
tDH
A7
D7-1
tCD
A8
Q8-1
A9
TIMING WAVEFORM OF SINGLE READ/WRITE CYCLE(ADSP CONTROLLED, ADSC=HIGH)
Q9-1
tOH
Undefined
Don′t Care
KM718V887
256Kx18 Synchronous SRAM
December 1998
Rev. 2.0
- 14
ZZ
Data Out
Data In
OE
ADV
CS
WRITE
ADDRESS
ADSC
ADSP
CLOCK
tCSS
tAS
tSS
A1
tLZOE
tOE
tCSH
tAH
tSH
Q1-1
ZZ Setup Cycle
tPDS
tHZC
Sleep State
ZZ Recovery Cycle
tPUS
tCL
tCYC
tCH
TIMING WAVEFORM OF POWER DOWN CYCLE
tWS
Normal Operation Mode
tHZOE
A2
D2-1
tWH
Undefined
Don′t Care
D2-2
KM718V887
256Kx18 Synchronous SRAM
December 1998
Rev. 2.0
KM718V887
256Kx18 Synchronous SRAM
APPLICATION INFORMATION
DEPTH EXPANSION
The Samsung 256Kx18 Synchronous Burst SRAM has two additional chip selects for simple depth expansion.
This permits easy secondary cache upgrades from 256K depth to 512K depth without extra logic.
I/O[0:71]
Data
Address
A[0:18]
A[18]
A[18]
A[0:17]
Address
CLK
Microprocessor
CS2
CS2
CS2
ADSC
CLK
Address
Data
CS2
CLK
Address
CLK
256Kx18
SB
SRAM
ADSC
OE
(Bank 0)
OE
256Kx18
SB
SRAM
(Bank 1)
CS1
CS1
ADV
Data
WEx
WEx
Cache
Controller
A[0:17]
ADV
ADSP
ADSP
ADS
INTERLEAVE READ TIMING (Refer to non-interleave write timing for interleave write timing)
(ADSP CONTROLLED , ADSC=HIGH)
CLOCK
tSS
tSH
ADSP
tAS
ADDRESS
[0:n]
A1
tAH
A2
tWS
tWH
WRITE
tCSS
tCSH
CS1
Bank 0 is selected by CS2, and Bank 1 deselected by CS2
An+1
tADVS
Bank 0 is deselected by CS2, and Bank 1 selected by CS2
tADVH
ADV
OE
tOE
Data Out
(Bank 0)
Data Out
(Bank 1)
tLZOE
tHZC
Q1-1
Q1-2
Q1-3
Q1-4
tCD
tLZC
Q2-1
Q2-2
*Notes : n = 14 32K depth, 15 64K depth, 16 128K depth, 17 256K depth
- 15
Q2-3
Q2-4
Don′t Care
Undefined
December 1998
Rev. 2.0
KM718V887
256Kx18 Synchronous SRAM
PACKAGE DIMENSIONS
100-TQFP-1420A
Units:millimeters/inches
0~8°
22.00 ±0.30
0.127 +- 0.10
0.05
20.00 ±0.20
16.00 ±0.30
14.00 ±0.20
0.10 MAX
(0.83)
0.50 ±0.10
#1
0.65
(0.58)
0.30 ±0.10
0.10 MAX
1.40 ±0.10 1.60 MAX
0.50 ±0.10
- 16
0.05 MIN
December 1998
Rev. 2.0