ALSC AS7C33256NTD18B

February 2005
AS7C33256NTD18B
®
3.3V 256K×18 Pipelined SRAM with NTDTM
Features
• Organization: 262,144 words × 18 bits
• NTD™ architecture for efficient bus operation
• Fast clock speeds to 200 MHz
• Fast clock to data access: 3.0/3.5/4.0 ns
• Fast OE access time: 3.0/3.5/4.0 ns
• Fully synchronous operation
• Asynchronous output enable control
• Available in 100-pin TQFP package
• Byte write enables
• Clock enable for operation hold
• Multiple chip enables for easy expansion
• 3.3V core power supply
• 2.5V or 3.3V I/O operation with separate VDDQ
• Self-timed write cycles
• Interleaved or linear burst modes
• Snooze mode for standby operation
Logic block diagram
18
A[17:0]
Q
D
Address
register
Burst logic
18
CLK
D
CE0
CE1
CE2
Q
Write delay
addr. registers
18
CLK
R/W
BWa
BWb
ADV / LD
LBO
ZZ
Write Buffer
DQ [a:b]
CLK
Control
logic
CLK
18
18
Data Q
Input
Register
D
256K x 18
18
CLK
SRAM
Array
18
18
CLK
CEN
CLK
OE
Output
Register
18
OE
DQ [a:b]
Selection Guide
-200
-166
-133
Units
5
6
7.5
ns
Maximum clock frequency
200
166
133
MHz
Maximum clock access time
3.0
3.5
4
ns
Maximum operating current
375
350
325
mA
Maximum standby current
135
120
110
mA
Maximum CMOS standby current (DC)
30
30
30
mA
Minimum cycle time
2/8/05; v.1.5
Alliance Semiconductor
P. 1 of 18
Copyright © Alliance Semiconductor. All rights reserved.
AS7C33256NTD18B
®
4 Mb Synchronous SRAM products list1,2
Org
256KX18
128KX32
128KX36
256KX18
128KX32
128KX36
256KX18
128KX32
128KX36
256KX18
128KX32
128KX36
256KX18
128KX32
128KX36
Part Number
AS7C33256PFS18B
AS7C33128PFS32B
AS7C33128PFS36B
AS7C33256PFD18B
AS7C33128PFD32B
AS7C33128PFD36B
AS7C33256FT18B
AS7C33128FT32B
AS7C33128FT36B
AS7C33256NTD18B
AS7C33128NTD32B
AS7C33128NTD36B
AS7C33256NTF18B
AS7C33128NTF32B
AS7C33128NTF36B
Mode
PL-SCD
PL-SCD
PL-SCD
PL-DCD
PL-DCD
PL-DCD
FT
FT
FT
NTD-PL
NTD-PL
NTD-PL
NTD-FT
NTD-FT
NTD-FT
Speed
200/166/133 MHz
200/166/133 MHz
200/166/133 MHz
200/166/133 MHz
200/166/133 MHz
200/166/133 MHz
6.5/7.5/8.0/10 ns
6.5/7.5/8.0/10 ns
6.5/7.5/8.0/10 ns
200/166/133 MHz
200/166/133 MHz
200/166/133 MHz
6.5/7.5/8.0/10 ns
6.5/7.5/8.0/10 ns
6.5/7.5/8.0/10 ns
1 Core Power Supply: VDD = 3.3V + 0.165V
2 I/O Supply Voltage: VDDQ = 3.3V + 0.165V for 3.3V I/O
VDDQ = 2.5V + 0.125V for 2.5V I/O
PL-SCD
PL-DCD
FT
NTD1-PL
NTD-FT
:
:
:
:
:
Pipelined Burst Synchronous SRAM - Single Cycle Deselect
Pipelined Burst Synchronous SRAM - Double Cycle Deselect
Flow-through Burst Synchronous SRAM
Pipelined Burst Synchronous SRAM with NTDTM
Flow-through Burst Synchronous SRAM with NTDTM
1NTD: No Turnaround Delay. NTDTM is a trademark of Alliance Semiconductor Corporation. All trademarks mentioned in this document are the property of
their respective owners.
2/8/05; v.1.5
Alliance Semiconductor
P. 2 of 18
AS7C33256NTD18B
®
NC
NC
NC
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
TQFP 14x20mm
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
A
NC
NC
VDDQ
VSSQ
NC
DQPa
DQa7
DQa6
VSSQ
VDDQ
DQa5
DQa4
VSS
NC
VDD
ZZ
DQa3
DQa2
VDDQ
VSSQ
DQa1
DQa0
NC
NC
VSSQ
VDDQ
NC
NC
NC
LBO
A
A
A
A
A1
A0
NC
NC
VSS
VDD
NC
NC
A
A
A
A
A
A
A
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
VDDQ
VSSQ
NC
NC
DQb0
DQb1
VSSQ
VDDQ
DQb2
DQb3
NC
VDD
NC
VSS
DQb4
DQb5
VDDQ
VSSQ
DQb6
DQb7
DQPb
NC
VSSQ
VDDQ
NC
NC
NC
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
A
A
CE0
CE1
NC
NC
BWb
BWa
CE2
VDD
VSS
CLK
R/W
CEN
OE
ADV/LD
NC
NC
A
A
Pin arrangement for TQFP (top view)
2/8/05; v.1.5
Alliance Semiconductor
P. 3 of 18
AS7C33256NTD18B
®
Functional description
The AS7C33256NTD18B family is a high performance CMOS 4 Mbit synchronous Static Random Access Memory (SRAM)
organized as 262,144 words × 18 bits and incorporates a LATE LATE Write.
This variation of the 4Mb sychronous SRAM uses the No Turnaround Delay (NTD™) architecture, featuring an enhanced
Write operation that improves bandwidth over pipeline burst devices. In a normal pipeline burst device, the write data,
command, and address are all applied to the device on the same clock edge. If a Read command follows this Write command,
the system must wait for two 'dead' cycles for valid data to become available. These dead cycles can significantly reduce
overall bandwidth for applications requiring random access or Read-Modify-Write operations.
NTD™ devices use the memory bus more efficiently by introducing a write 'latency' which matches the two (one)cycle
pipeline (flowthrough) read latency. Write data is applied two cycles after the Write command and address, allowing the Read
pipeline to clear. With NTD™, Write and Read operations can be used in any order without producing dead bus cycles.
Assert R/W low to perform Write cycles. Byte Write enable controls write access to specific bytes, or can be tied low for full
18 bit writes. Write enable signals, along with the write address, are registered on a rising edge of the clock. Write data is
applied to the device two clock cycles later. Unlike some asynchronous SRAMs, output enable OE does not need to be toggled
for write operations; it can be tied low for normal operations. Outputs go to a high impedance state when the device is deselected by any of the three chip enable inputs (refer to Synchronous truth table on page 6). In pipeline mode, a two cycle
deselect latency allows pending read or write operations to be completed.
Use the ADV (burst advance) input to perform burst read, write and deselect operations. When ADV is high, external addresses, chip
select, R/W pins are ignored, and internal address counters increment in the count sequence specified by the LBO control. Any
device operations, including burst, can be stalled using the CEN=1 the clock enable input.
The AS7C33256NTD18B operates with a 3.3V ± 5% power supply for the device core (VDD). DQ circuits use a separate
power supply (VDDQ) that operates across 3.3V or 2.5V ranges. These devices are available in a 100-pin 14×20 mm TQFP
package.
TQFP Capacitance
Parameter
Input capacitance
I/O capacitance
Symbol
Test conditions
Min
Max
Unit
CIN*
CI/O*
Vin = 0V
-
5
pF
Vin = Vout = 0V
-
7
pF
Symbol
Typical
Units
1–layer
θJA
40
°C/W
4–layer
θJA
22
°C/W
θJC
8
°C/W
*Guranteed not tested
TQFP thermal resistance
Description
Thermal resistance
(junction to ambient)1
Thermal resistance
(junction to top of case)1
Conditions
Test conditions follow standard test methods and
procedures for measuring thermal impedance,
per EIA/JESD51
1 This parameter is sampled
2/8/05; v.1.5
Alliance Semiconductor
P. 4 of 18
AS7C33256NTD18B
®
Signal descriptions
Signal
I/O Properties Description
CLK
I
CLOCK
Clock. All inputs except OE, LBO, and ZZ are synchronous to this clock.
CEN
I
SYNC
Clock enable. When de-asserted HIGH, the clock input signal is masked.
A, A0, A1
I
SYNC
Address. Sampled when all chip enables are active and ADV/LD is asserted.
DQ[a,b]
I/O
SYNC
Data. Driven as output when the chip is enabled and OE is active.
CE0, CE1,
CE2
I
SYNC
Synchronous chip enables. Sampled at the rising edge of CLK, when ADV/LD is asserted.
Are ignored when ADV/LD is HIGH.
ADV/LD
I
SYNC
Advance or Load. When sampled HIGH, the internal burst address counter will increment
in the order defined by the LBO input value. When LOW, a new address is loaded.
R/W
I
SYNC
A HIGH during LOAD initiates a READ operation. A LOW during LOAD initiates a
WRITE operation. Is ignored when ADV/LD is HIGH.
BW[a,b]
I
SYNC
Byte write enables. Used to control write on individual bytes. Sampled along with WRITE
command and BURST WRITE.
OE
I
ASYNC
Asynchronous output enable. I/O pins are not driven when OE is inactive.
LBO
I
STATIC
Selects Burst mode. When tied to VDD or left floating, device follows interleaved Burst
order. When driven Low, device follows linear Burst order. This signal is internally pulled
High.
ZZ
I
ASYNC
Snooze. Places device in low power mode; data is retained. Connect to GND if unused.
NC
-
-
No connects.
Snooze Mode
SNOOZE MODE is a low current, power-down mode in which the device is deselected and current is reduced to ISB2. The duration of
SNOOZE MODE is dictated by the length of time the ZZ is in a High state.
The ZZ pin is an asynchronous, active high input that causes the device to enter SNOOZE MODE.
When the ZZ pin becomes a logic High, ISB2 is guaranteed after the time tZZI is met. After entering SNOOZE MODE, all inputs except ZZ
is disabled and all outputs go to High-Z. Any operation pending when entering SNOOZE MODE is not guaranteed to successfully complete.
Therefore, SNOOZE MODE (READ or WRITE) must not be initiated until valid pending operations are completed. Similarly, when exiting
SNOOZE MODE during tPUS, only a DESELECT or READ cycle should be given while the SRAM is transitioning out of SNOOZE
MODE.
Burst order
Interleaved burst order (LBO = 1)
Linear burst order (LBO = 0)
A1 A0
A1 A0
A1 A0
A1 A0
Starting address
0 0
0 1
1 0
1 1
First increment
0 1
0 0
1 1
Second increment
1 0
1 1
Third increment
1 1
1 0
2/8/05; v.1.5
A1 A0
A1 A0
A1 A0
A1 A0
Starting Address
0 0
0 1
1 0
1 1
1 0
First increment
0 1
1 0
1 1
0 0
0 0
0 1
Second increment
1 0
1 1
0 0
0 1
0 1
00
Third increment
1 1
0 0
0 1
1 0
Alliance Semiconductor
P. 5 of 18
AS7C33256NTD18B
®
Synchronous truth table[5,6,7,8,9,11]
CE0
CE1 CE2 ADV/LD R/W
BWn
OE
CEN
Address
source
CLK
Operation
DQ
H
X
X
L
X
X
X
L
NA
L to H
DESELECT Cycle
High-Z
X
X
H
L
X
X
X
L
NA
L to H
DESELECT Cycle
High-Z
X
L
X
L
X
X
X
L
NA
L to H
DESELECT Cycle
High-Z
X
X
X
H
X
X
X
L
NA
L to H
CONTINUE DESELECT Cycle
High-Z
L
H
L
L
H
X
L
L
READ Cycle (Begin Burst)
Q
X
X
X
H
X
X
L
L
READ Cycle (Continue Burst)
Q
L
H
L
L
H
X
H
L
X
X
X
H
X
X
H
L
L
H
L
L
L
L
X
L
X
X
X
H
X
L
X
L
L
H
L
L
L
H
X
L
X
X
X
H
X
H
X
L
X
X
X
X
X
X
X
H
External L to H
Next
L to H
External L to H NOP/DUMMY READ (Begin Burst) High-Z
Next
L to H
External L to H
Next
L to H
DUMMY READ (Continue Burst)
L to H
Current L to H
Alliance Semiconductor
1,10
2
High-Z 1,2,10
D
3
WRITE CYCLE (Continue Burst)
D
1,3,10
High-Z
2,3
WRITE ABORT (Continue Burst)
High-Z
1,2,3,
10
INHIBIT CLOCK
-
4
Key: X = Don’t Care, H = HIGH, L = LOW. BWn = H means all byte write signals (BWa and BWb) are HIGH. BWn = L means one or more byte write signals are LOW.
Notes:
1 CONTINUE BURST cycles, whether READ or WRITE, use the same control inputs. The type of cycle performed (READ or WRITE) is chose in the initial BEGIN BURST cycle.
A CONINUE DESELECT cycle can only be entered if a DESELECT CYCLE is executed first.
2 DUMMY READ and WRITE ABORT cycles can be considered NOPs because the device performs no external operation. A WRITE ABORT means a WRITE command is given,
but no operation is performed.
3 OE may be wired LOW to minimize the number of control signal to the SRAM. The device will automatically turn off the output drivers during a WRITE cycle. OE may be used
when the bus turn-on and turn-off times do not meet an application’s requirements.
4 If an INHIBIT CLOCK command occurs during a READ operation, the DQ bus will remain active (Low-Z). If it occurs during a WRITE cycle, the bus will remain in High-Z. No
WRITE operations will be performed during the INHIBIT CLOCK cycle.
5 BWa enables WRITEs to byte “a” (DQa pins); BWb enables WRITEs to byte “b” (DQb pins).
6 All inputs except OE and ZZ must meet setup and hold times around the rising edge (LOW to HIGH) of CLK.
7 Wait states are inserted by setting CEN HIGH.
8 This device contains circuitry that will ensure that the outputs will be in High-Z during power-up.
9 The device incorporates a 2-bit burst counter. Address wraps to the initial address every fourth BURST CYCLE.
10 The address counter is incremented for all CONTINUE BURST cycles.
11 ZZ pin is always Low.
2/8/05; v.1.5
1
WRITE CYCLE (Begin Burst)
External L to H NOP/WRITE ABORT (Begin Burst)
Next
Notes
P. 6 of 18
AS7C33256NTD18B
®
State diagram for NTD SRAM
Read
Burst
Read
Burs
Dsel
Dse
l
Rea
d
Dsel
Writ
Dsel
l
Dse
ite
Wr
Burst
Burst
Dsel
W
rit
e
ad
Re
Write
Read
Write
Burst
Read
Burst
Burst
Write
Absolute maximum ratings
Parameter
Symbol
Min
Max
Unit
VDD, VDDQ
–0.5
+4.6
V
Input voltage relative to GND (input pins)
VIN
–0.5
VDD + 0.5
V
Input voltage relative to GND (I/O pins)
VIN
–0.5
VDDQ + 0.5
V
Pd
–
1.8
W
Short circuit output current
IOUT
–
20
mA
Storage temperature
Tstg
–65
+150
oC
Temperature under bias
Tbias
–65
+135
oC
Power supply voltage relative to GND
Power dissipation
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 outside those indicated in the operational sections of this specification is not implied. Exposure to
absolute maximum rating conditions may affect reliability.
Recommended operating conditions at 3.3V I/O
Parameter
Symbol
Min
Nominal
Max
Unit
Supply voltage for inputs
VDD
3.135
3.3
3.465
V
Supply voltage for I/O
VDDQ
3.135
3.3
3.465
V
Vss
0
0
0
V
Symbol
Min
Nominal
Max
Unit
Supply voltage for inputs
VDD
3.135
3.3
3.465
V
Supply voltage for I/O
VDDQ
2.375
2.5
2.625
V
Vss
0
0
0
V
Ground supply
Recommended operating conditions at 2.5V I/O
Parameter
Ground supply
2/8/05; v.1.5
Alliance Semiconductor
P. 7 of 18
AS7C33256NTD18B
®
DC electrical characteristics for 3.3V I/O operation
Parameter
Sym
Conditions
Min
Max
Unit
current†
|ILI|
VDD = Max, 0V < VIN < VDD
-2
2
µA
Output leakage current
|ILO|
OE ≥ VIH, VDD = Max, 0V < VOUT < VDDQ
-2
2
µA
Input high (logic 1) voltage
VIH
Address and control pins
2*
VDD+0.3
I/O pins
2*
VDDQ+0.3
Input low (logic 0) voltage
VIL
Address and control pins
-0.3**
0.8
I/O pins
-0.5**
0.8
Output high voltage
VOH
IOH = –4 mA, VDDQ = 3.135V
2.4
–
V
Output low voltage
VOL
IOL = 8 mA, VDDQ = 3.465V
–
0.4
V
Input leakage
V
V
DC electrical characteristics for 2.5V I/O operation
Parameter
Sym
Conditions
Min
Max
Unit
Input leakage current†
|ILI|
VDD = Max, 0V < VIN < VDD
-2
2
µA
Output leakage current
|ILO|
OE ≥ VIH, VDD = Max, 0V < VOUT < VDDQ
-2
2
µA
Input high (logic 1) voltage
VIH
Address and control pins
1.7*
VDD+0.3
V
I/O pins
1.7*
VDDQ+0.3
V
Input low (logic 0) voltage
VIL
Address and control pins
-0.3**
0.7
V
I/O pins
-0.3**
0.7
V
Output high voltage
VOH
IOH = –4 mA, VDDQ = 2.375V
1.7
–
V
Output low voltage
VOL
IOL = 8 mA, VDDQ = 2.625V
–
0.7
V
† LBO and ZZ pins have an internal pull-up or pull-down, and input leakage = ±10 µA.
*
VIH max < VDD +1.5V for pulse width less than 0.2 X tCYC
**V
IL min
= -1.5 for pulse width less than 0.2 X tCYC
IDD operating conditions and maximum limits
Parameter
Sym
Operating power supply
current1
ICC
ISB
Standby power supply
current
Test conditions
CE0 < VIL, CE1 > VIH, CE2 < VIL, f = fMax,
IOUT = 0 mA, ZZ < VIL
All VIN ≤ 0.2V or > VDD – 0.2V, Deselected,
f = fMax, ZZ < VIL
-200
-166
-133
Unit
375
350
325
mA
135
120
110
ISB1
Deselected, f = 0, ZZ < 0.2V,
all VIN ≤ 0.2V or ≥ VDD – 0.2V
30
30
30
ISB2
Deselected, f = fMax, ZZ ≥ VDD – 0.2V,
all VIN ≤ VIL or ≥ VIH
30
30
30
mA
1 ICC given with no output loading. ICC increases with faster cycle times and greater output loading.
2/8/05; v.1.5
Alliance Semiconductor
P. 8 of 18
AS7C33256NTD18B
®
Timing characteristics over operating range
-200
Parameter
-166
-133
Notes1
Sym
Min
Max
Min
Max
Min
Max
Unit
Clock frequency
fMAX
–
200
-
166
-
133
MHz
Cycle time
tCYC
5
–
6
-
7.5
-
ns
Clock access time
tCD
–
3.0
-
3.5
-
4.0
ns
Output enable Low to data valid
tOE
–
3.0
-
3.5
-
4.0
ns
Clock High to output Low Z
tLZC
0
–
0
-
0
-
ns
2,3,4
Data output invalid from clock High
tOH
1.5
–
1.5
-
1.5
-
ns
4
Output enable Low to output Low Z
tLZOE
0
–
0
-
0
-
ns
2,3,4
Output enable High to output High Z
tHZOE
–
3.0
-
3.5
-
4.0
ns
2,3,4
Clock High to output High Z
tHZC
–
3.0
-
3.5
-
4.0
ns
2,3,4
Clock High to output High Z
tHZCN
–
1.5
-
1.5
-
2.0
ns
5
Clock High pulse width
tCH
2.0
–
2.4
-
2.5
-
ns
6
Clock Low pulse width
tCL
2.3
–
2.4
-
2.5
-
ns
6
Address setup to clock High
tAS
1.4
–
1.5
-
1.5
-
ns
7
Data setup to clock High
tDS
1.4
–
1.5
-
1.5
-
ns
7
Write setup to clock High
tWS
1.4
–
1.5
-
1.5
-
ns
7
Chip select setup to clock High
tCSS
1.4
–
1.5
-
1.5
-
ns
7
Clock enable setup to clock High
tCENS
1.4
–
1.5
-
1.5
-
ns
7
ADV/LD setup to clock High
tADVS
1.4
–
1.5
-
1.5
-
ns
7
Address hold from clock High
tAH
0.4
–
0.5
-
0.5
-
ns
7
Data hold from clock High
tDH
0.4
–
0.5
-
0.5
-
ns
7
Write hold from clock High
tWH
0.4
–
0.5
-
0.5
-
ns
7
ADV/LD hold from clock High
tADVH
0.4
–
0.5
-
0.5
-
ns
7
Clock enable hold from clock High
tCENH
0.4
–
0.5
-
0.5
-
ns
7
tCSH
0.4
–
0.5
-
0.5
-
ns
7
Chip select hold from clock High
1 See “Notes” on page 15.
Snooze Mode Electrical Characteristics
Description
Current during Snooze Mode
ZZ active to input ignored
ZZ inactive to input sampled
ZZ active to SNOOZE current
ZZ inactive to exit SNOOZE current
2/8/05; v.1.5
Conditions
Symbol
ZZ > VIH
ISB2
tPDS
tPUS
tZZI
tRZZI
Alliance Semiconductor
Min
Max
Units
30
mA
cycle
cycle
cycle
cycle
2
2
2
0
P. 9 of 18
AS7C33256NTD18B
®
Key to switching waveforms
Rising input
don’t care
Falling input
Undefined
Timing waveform of read cycle
tCH
tCL
tCYC
CLK
tCES tCEH
CEN
tAS
Address
tAH
A1
A2
A3
tWS tWH
R/W
tWS tWH
BWn
tCSH
CE0,CE2
CE1
tADVS tADVH
ADV/LD
OE
tOE
tLZOE
Dout
tHZOE
Q(A1)
tHLZC
Q(A2Y‘10)
Q(A2)
Q(A2Y‘11)
Q(A2Y‘01)
Read
Q(A1)
2/8/05; v.1.5
DSEL
Read
Q(A2)
Continue
Read
Q(A2Y‘01)
Continue
Read
Q(A2Y‘10)
Continue
Read
Q(A2Y‘11)
Alliance Semiconductor
Q(A3)
Inhibit
Clock
Read
Q(A3)
Continue
Read
Q(A3Y‘01)
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Timing waveform of write cycle
tCH
tCL
tCYC
CLK
tCES tCEH
CEN
tAS
Address
tAH
A1
A2
A3
R/W
BWn
tCSH
CE0,CE2
CE1
tADVS tADVH
ADV/LD
OE
tDS
D(A1)
Din
Q(n-2)
D(A2Y‘01)
D(A2Y‘10)
D(A2Y‘11)
Q(n-1)
Write
D(A1)
2/8/05; v.1.5
D(A3)
D(A2)
tHZOE
Dout
tDH
DSEL
Write
D(A2)
Continue
Write
D(A2Y‘01)
Continue
Write
D(A2Y‘10)
Continue
Write
D(A2Y‘11)
Alliance Semiconductor
Inhibit
Clock
Write
D(A3)
Continue
Write
D(A3Y‘01)
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Timing waveform of read/write cycle
tCH
tCL
tCYC
CLK
tCENS
tCENH
CEN
CE1
tCSS
tCSH
CE0, CE2
tADVS
tADVH
ADV/LD
tWS
tWH
tWS
tWH
tAS
tAH
R/W
BWn
ADDRESS
A1
A3
A2
A4
A6
A5
A7
tCD
tDS tDH
D/Q
D(A1)
tLZC
D(A2)
D(A2Ý01)
tOH
tOE
Q(A3)
Q(A4)
tHZC
Q(A4Ý01)
D(A5)
Q(A6)
tHZOE
tLZOE
OE
Command
Write
D(A1)
Write
D(A2)
Burst
Write
D(A2Ý01)
Read
Q(A3)
Read
Q(A4)
Burst
Read
Q(A4Ý01)
Write
D(A5)
Read
Q(A6)
Write
D(A7)
DSEL
Note: Ý = XOR when LBO = high/no connect. Ý = ADD when LBO = low. BW[a:d] is don’t care.
2/8/05; v.1.5
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NOP, stall and deselect cycles
CLK
CEN
CE1
CE0, CE2
ADV/LD
R/W
BWn
Address
A2
A1
Q(A1)
D/Q
Command
Read
Q(A1)
Burst
Q(A1Ý01)
STALL
Q(A1Ý01)
Burst
Q(A1Ý10)
A3
D(A2)
Q(A1Ý10)
DSEL
Burst
DSEL
Write
D(A2)
Burst
NOP
D(A2Ý01)
Burst
D(A2Ý10)
Write
NOP
D(A3)
Note: Ý = XOR when LBO = high/no connect; Ý = ADD when LBO = low. OE is low.
2/8/05; v.1.5
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P. 13 of 18
AS7C33256NTD18B
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Timing waveform of snooze mode
CLK
tPUS
ZZ setup cycle
ZZ recovery cycle
ZZ
tZZI
Isupply
ISB2
tRZZI
All inputs
(except ZZ)
Deselect or Read Only
Deselect or Read Only
Normal
operation
Cycle
Dout
2/8/05; v.1.5
High-Z
Alliance Semiconductor
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AC test conditions
•
•
•
•
Output Load: see Figure B, except for tLZC, tLZOE, tHZOE, tHZC see Figure C.
Input pulse level: GND to 3V. See Figure A.
Input rise and fall time (Measured at 0.3V and 2.7V): 2 ns. See Figure A.
Input and output timing reference levels: 1.5V.
+3.0V
90%
10%
GND
90%
10%
Figure A: Input waveform
Dout
Z0=50Ω
50Ω
VL=1.5V
30 pF*
Figure B: Output load (A)
Notes:
6
1 For test conditions, see AC Test Conditions, Figures A, B, C.
2 This parameter measured with output load condition in Figure C
7
3 This parameter is sampled and not 100% tested.
4 tHZOE is less than tLZOE; and tHZC is less than tLZC at any given temperature and voltage.
5 tHZCN is a‘no load’ parameter to indicate exactly when SRAM outputs
have stopped driving.
2/8/05; v.1.5
Thevenin equivalent:
+3.3V for 3.3V I/O;
/+2.5V for 2.5V I/O
DOUT
353Ω / 1538Ω
319Ω / 1667Ω
5 pF*
GND *including scope
and jig capacitance
Figure C: Output load (B)
tCH measured as HIGH above VIH, and tCL measured as LOW below
VIL
This is a synchronous device. All addresses must meet the specified
setup and hold times for all rising edges of CLK. All other synchronous
inputs must meet the setup and hold times with stable logic levels for all
rising edges of CLK when chip is enabled.
Alliance Semiconductor
P. 15 of 18
AS7C33256NTD18B
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Package Dimensions: 100-pin quad flat pack (TQFP)
Hd
A1
A2
b
c
D
E
e
Hd
He
L
L1
a
TQFP
Min
Max
0.05
0.15
1.35
1.45
0.22
0.38
0.09
0.20
13.90
14.10
19.90
20.10
0.65 nominal
15.90
16.10
21.90
22.10
0.45
0.75
1.00 nominal
0°
7°
Dimensions in
millimeters
D
b
e
He E
α
c
L1
L
2/8/05; v.1.5
Alliance Semiconductor
A1 A2
P. 16 of 18
AS7C33256NTD18B
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Ordering information
Package
Width
-200
-166
-133
TQFP
×18
AS7C33256NTD18B-200TQC
AS7C33256NTD18B-166TQC
AS7C33256NTD18B-133TQC
TQFP
×18
AS7C33256NTD18B-200TQI
AS7C33256NTD18B-166TQI
AS7C33256NTD18B-133TQI
Note: Add suffix ‘N’ to the above part numbers for lead free parts (Ex AS7C33256NTD18B-166TQCN)
Part numbering guide
AS7C
33
256
NTD
18
B
–XXX
TQ
C/I
X
1
2
3
4
5
6
7
8
9
10
1.Alliance Semiconductor SRAM prefix
2.Operating voltage: 33=3.3V
3.Organization: 256=256K
4.NTDTM=No Turn-around Delay, Pipelined mode.
5.Organization: 18=x18
6.Production version: B = Product revision
7.Clock speed (MHz)
8.Package type: TQ=TQFP
9.Operating temperature: C=Commercial (0° C to 70° C); I=Industrial (-40° C to 85° C)
10. N = Lead Free Part
2/8/05; v.1.5
Alliance Semiconductor
P. 17 of 18
AS7C33256NTD18B
®
®
Alliance Semiconductor Corporation
Copyright © Alliance Semiconductor
2575, Augustine Drive,
All Rights Reserved
Santa Clara, CA 95054
Part Number: AS7C33256NTD18B
Tel: 408 - 855 - 4900
Document Version: v.1.5
Fax: 408 - 855 - 4999
www.alsc.com
© Copyright 2003 Alliance Semiconductor Corporation. All rights reserved. Our three-point logo, our name and Intelliwatt are trademarks or registered
trademarks of Alliance. All other brand and product names may be the trademarks of their respective companies. Alliance reserves the right to make
changes to this document and its products at any time without notice. Alliance assumes no responsibility for any errors that may appear in this document.
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