November 2004
Copyright © Alliance Semiconductor. All rights reserved.
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AS7C33256NTD32A
AS7C33256NTD36A
11/30/04, v. 2.1 Alliance Semiconductor P. 1 of 19
3.3V 256K×32/36 Pipelined burst Synchronous SRAM with NTDTM
Features
• Organization: 262,144 words × 32 or 36 bits
•NTD
™architecture for efficient bus operation
• Fast clock speeds to 166 MHz
• Fast clock to data access: 3.5/4.0 ns
•Fast OE
access time: 3.5/4.0 ns
• Fully synchronous operation
• Common data inputs and data outputs
• Asynchronous output enable control
• Available in 100-pin TQFP
• Byte write enables
• Clock enable for operation hold
• Multiple chip enables for easy expansion
• 3.3 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
Selection Guide
-166 -133 Units
Minimum cycle time 6 7.5 ns
Maximum clock frequency 166 133 MHz
Maximum clock access time 3.5 4 ns
Maximum operating current 475 400 mA
Maximum standby current 130 100 mA
Maximum CMOS standby current (DC) 30 30 mA
Write Buffer
Address
DQ
CLK
register
Output
Register
DQ[a:d]
36/32
36/32
18
18
CLK
CE0
CE1
CE2
A[17:0]
OE
CLK
CEN
Control
CLK
logic
Data
DQ
CLK
Input
Register
36/32 36/32
36/32
OE
256K x 32/36
SRAM
Array
R/W
DQ [a:d]
BWa
BWc
BWb
BWd
CLK
Q
D
ADV / LD
LBO
Burst logic
addr. registers
Write delay
36/32
18
ZZ
CLK
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AS7C33256NTD32A
AS7C33256NTD36A
11/30/04, v. 2.1 Alliance Semiconductor P. 2 of 19
8 Mb Synchronous SRAM products list1,2
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 : Pipelined Burst Synchronous SRAM - Single Cycle Deselect
PL-DCD : Pipelined Burst Synchronous SRAM - Double Cycle Deselect
FT : Flow-through Burst Synchronous SRAM
NTD1-PL : Pipelined Burst Synchronous SRAM with NTDTM
NTD-FT : Flow-through Burst Synchronous SRAM with NTDTM
Org Part Number Mode Speed
512KX18 AS7C33512PFS18A PL-SCD 166/133 MHz
256KX32
AS7C33256PFS32A PL-SCD 166/133 MHz
256KX36 AS7C33256PFS36A PL-SCD 166/133 MHz
512KX18 AS7C33512PFD18A PL-DCD 166/133 MHz
256KX32
AS7C33
256
PFD32A PL-DCD 166/133 MHz
256KX36 AS7C33
256
PFD36A PL-DCD 166/133 MHz
512KX18 AS7C33512FT18A FT 7.5/8.5/10 ns
256KX32
AS7C33
256
FT32A FT 7.5/8.5/10 ns
256KX36 AS7C33
256
FT36A FT 7.5/8.5/10 ns
512KX18 AS7C33512NTD18A NTD-PL 166/133 MHz
256KX32
AS7C33
256
NTD32A NTD-PL 166/133 MHz
256KX36 AS7C33
256
NTD36A NTD-PL 166/133 MHz
512KX18 AS7C33512NTF18A NTD-FT 7.5/8.5/10 ns
256KX32
AS7C33
256
NTF32A NTD-FT 7.5/8.5/10 ns
256KX36 AS7C33
256
NTF36A NTD-FT 7.5/8.5/10 ns
1. NTD: No Turnaround Delay. NTDTM is a trademark of Alliance Semiconductor Corporation. All trademarks mentioned in this document are the property
of their respective owners.
®
AS7C33256NTD32A
AS7C33256NTD36A
11/30/04, v. 2.1 Alliance Semiconductor P. 3 of 19
Pin arrangement for TQFP (top view)
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
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
LBO
A
A
A
A
A1
A0
NC
NC
V
SS
V
DD
NC
NC
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
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
A
A
CE0
CE1
BWd
BWc
BWb
BWa
CE2
V
DD
V
SS
CLK
R/W
CEN
OE
ADV/LD
NC
A
A
A
TQFP 14x20mm
A
DQPc/NC
DQc0
DQc1
V
DDQ
V
SSQ
DQc2
DQc3
DQc4
DQc5
V
SSQ
V
DDQ
DQc6
DQc7
NC
V
DD
NC
V
SS
DQd0
DQd1
V
DDQ
V
SSQ
DQd2
DQd3
DQd4
DQd5
V
SSQ
V
DDQ
DQd6
DQd7
DQPd/NC
DQPb/NC
DQb7
DQb6
V
DDQ
V
SSQ
DQb5
DQb4
DQb3
DQb2
V
SSQ
V
DDQ
DQb1
DQb0
V
ss
ZZ
DQa7
DQa6
V
DDQ
V
SSQ
DQa5
DQa4
DQa3
DQa2
V
SSQ
V
DDQ
DQa1
DQa0
DQP/NC
V
DD
NC
Note: Pins 1, 30, 51 , and 80 are NC for ×32
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AS7C33256NTD32A
AS7C33256NTD36A
11/30/04, v. 2.1 Alliance Semiconductor P. 4 of 19
Functional description
The AS7C33256NTD32/36A family is a high performance CMOS 8 Mbit synchronous Static Random Access Memory (SRAM) organized
as 262,144 words × 32 or 36 bits and incorporates a LATE LATE Write.
This variation of the 8Mb sychronous SRAM uses the No Turnaround Delay (NTD™) architecture, featuring an enhanced write operation
that improves bandwidth over pipelined burst devices. In a normal pipelined 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-cycle pipelined or one-cycle
flow-through 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 32/36 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 de-selected by any of the three chip enable inputs. In pipelined
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 AS7C33256NTD36A and AS7C33256NTD32A operate 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
*Guaranteed not tested
TQFP thermal resistance
Capacitance
Parameter Symbol Test conditions Min Max Unit
Input capacitance CIN*Vin = 0V - 5 pF
I/O capacitance CI/O*Vin = Vout = 0V - 7 pF
Description Conditions Symbol Typical Units
Thermal resistance
(junction to ambient)1
1 This parameter is sampled
Test conditions follow standard test methods
and procedures for measuring thermal
impedance, per EIA/JESD51
1–layer θJA 40 °C/W
4–layer θJA 22 °C/W
Thermal resistance
(junction to top of case)1θJC 8°C/W
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AS7C33256NTD32A
AS7C33256NTD36A
11/30/04, v. 2.1 Alliance Semiconductor P. 5 of 19
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.
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,c,d] 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. (refer to table on page 2) 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,c,d] 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 ISTATIC
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 connect. Note that pin 84 will be used for future address expansion to 16Mb density.
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AS7C33256NTD36A
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Synchronous truth table[5,6,7,8,9]
Key: X = Don’t Care, H = HIGH, L = LOW. BWn = H means all byte write signals (BWa, BWb, BWc, and BWd) 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/balls); BWb enables WRITEs to byte “b” (DQb pins/balls); BWc enables WRITEs to byte “c” (DQc pins/
balls); BWd enables WRITEs to byte “d” (DQd pins/balls).
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 in this truth table.
Burst Order
Interleaved Burst Order (LBO=1) Linear Burst Order (LBO=0)
A1 A0 A1 A0 A1 A0 A1 A0 A1 A0 A1 A0 A1 A0 A1 A0
Starting Address 0 0 0 1 1 0 1 1 Starting Address 0 0 0 1 1 0 1 1
First increment 0 1 0 0 1 1 1 0 First increment 0 1 1 0 1 1 0 0
Second increment 1 0 1 1 0 0 0 1 Second increment 1 0 1 1 0 0 0 1
Third increment 1 1 1 0 0 1 0 0 Third increment 1 1 0 0 0 1 1 0
CE0 CE1 CE2 ADV/LD R/W BWnOE CEN
Address
source CLK Operation DQ Notes
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 1
L H L L H X L L External L to H READ Cycle (Begin Burst) Q
X X X H X X L L Next L to H READ Cycle (Continue Burst) Q 1,10
L H L L H X H L External L to H NOP/DUMMY READ (Begin Burst) High-Z 2
X X X H X X H L Next L to H DUMMY READ (Continue Burst) High-Z 1,2,10
L H L L L L X L External L to H WRITE CYCLE (Begin Burst) D 3
X X X H X L X L Next L to H WRITE CYCLE (Continue Burst) D 1,3,10
L H L L L H X L External L to H NOP/WRITE ABORT (Begin Burst) High-Z 2,3
X X X H X H X L Next L to H WRITE ABORT (Continue Burst) High-Z 1,2,3,
10
X X X X X X X H Current L to H INHIBIT CLOCK - 4
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AS7C33256NTD36A
11/30/04, v. 2.1 Alliance Semiconductor P. 7 of 19
State Diagram for NTD SRAM
Recommended operating conditions at 3.3V I/O
Recommended operating conditions at 2.5V I/O
Absolute maximum ratings1
1 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.
Parameter Symbol Min Max Unit
Power supply voltage relative to GND 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
Power dissipation PD–1.8W
DC output current IOUT –50mA
Storage temperature (plastic) Tstg –65 +150 oC
Temperature under bias (Junction) Tbias –65 +150 oC
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
Ground supply Vss 0 0 0 V
Parameter 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
Ground supply Vss 0 0 0 V
Dsel
Dsel
Read
Read
Burst
Burst
Write
Read
Write
Burst
Read
Read
Write
Dsel
Read
Burst
Write
Dsel
Dsel
Write
Write
Burst
Dsel
Burst
Burst
Write
Read
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AS7C33256NTD36A
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DC electrical characteristics for 3.3V I/O operation
DC electrical characteristics for 2.5V I/O operation
*VIH max < VDD +1.5V for pulse width less than 0.2 X tCYC
**VIL min = -1.5 for pulse width less than 0.2 X tCYC
IDD operating conditions and maximum limits
Parameter Sym Conditions Min Max Unit
Input leakage current1
1 LBO, and ZZ pins have an internal pull-up or pull-down, and input leakage = ±10 µA.
|ILI|V
DD = 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 V
I/O pins 2*VDDQ+0.3
Input low (logic 0) voltage VIL
Address and control pins -0.3** 0.8 V
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
Parameter Sym Conditions Min Max Unit
Input leakage current |ILI|V
DD = 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
Parameter Sym Test conditions -166 -133 Unit
Operating power supply
current1
1 ICC given with no output loading. ICC increases with faster cycle times and greater output loading.
ICC
CE0 < VIL, CE1 > VIH, CE2 < VIL, f = fMax,
IOUT = 0 mA, ZZ < VIL
475 400 mA
Standby power supply current
ISB
All VIN ≤ 0.2V or >
V
DD
– 0.2V,
Deselected,
f = fMax, ZZ < VIL
130 100
mA
ISB1
Deselected, f = 0, ZZ < 0.2V,
all VIN ≤ 0.2V or ≥ VDD – 0.2V 30 30
ISB2
Deselected, f = f
Max
, ZZ
≥
V
DD
– 0.2V,
all VIN ≤ VIL or ≥ VIH
30 30
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Timing characteristics for 3.3 V I/O operation
Parameter Symbol
–166 –133
Unit Notes1
1 Refer to “notes” on page 16.
Min Max Min Max
Clock frequency
fMax – 166 – 133 MHz
Cycle time
tCYC 6–7.5– ns
Clock access time
tCD –3.5–4.0 ns
Output enable low to data valid
tOE –3.5–4.0 ns
Clock high to output low Z
tLZC 0 – 0 – ns 2,3,4
Data output invalid from clock high
tOH 1.5–1.5– ns 2
Output enable low to output low Z
tLZOE 0 – 0 – ns 2,3,4
Output enable high to output High Z
tHZOE – 3.5 – 4.0 ns 2,3,4
Clock high to output High Z
tHZC – 3.5 – 4.0 ns 2,3,4
Output enable high to invalid output
tOHOE 0–0– ns
Clock high pulse width
tCH 2.4–2.5– ns 5
Clock low pulse width
tCL 2.3–2.5– ns 5
Address and control setup to clock high
tAS 1.5–1.5– ns 6
Data setup to clock high
tDS 1.5–1.5– ns 6
Write setup to clock high
tWS 1.5 – 1.5 – ns 6,7
Chip select setup to clock high
tCSS 1.5 – 1.5 – ns 6,8
Address hold from clock high
tAH 0.5–0.5– ns 6
Data hold from clock high
tDH 0.5–0.5– ns 6
Write hold from clock high
tWH 0.5 – 0.5 – ns 6,7
Chip select hold from clock high
tCSH 0.5 – 0.5 – ns 6,8
Clock enable
setup to clock high
tCENS 1.5–1.5– ns 6
Clock enable hold from clock high
tCENH 0.5–0.5– ns 6
ADV/LD
setup to clock high
tADVS 1.5–1.5– ns 6
ADV/LD
hold from clock high
tADVH 0.5–0.5– ns 6
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Snooze Mode Electrical Characteristics
Timing characteristics for 2.5 V I/O operation
Parameter Symbol
–166 –133
Unit Notes1
Min Max Min Max
Clock frequency
fMax – 166 – 133 MHz
Cycle time
tCYC 6–7.5–ns
Clock access time
tCD – 3.8 – 4.2 ns
Output enable low to data valid
tOE – 3.5 – 4.0 ns
Clock high to output low Z
tLZC 0 – 0 – ns 2,3,4
Data output invalid from clock high
tOH 1.5–1.5– ns 2
Output enable low to output low Z
tLZOE 0 – 0 – ns 2,3,4
Output enable high to output High Z
tHZOE – 3.5 – 4.0 ns 2,3,4
Clock high to output High Z
tHZC – 3.5 – 4.0 ns 2,3,4
Output enable high to invalid output
tOHOE 0–0–ns
Clock high pulse width
tCH 2.4–2.5– ns 5
Clock low pulse width
tCL 2.3–2.5– ns 5
Address setup to clock high
tAS 1.7–1.7– ns 6
Data setup to clock high
tDS 1.7–1.7– ns 6
Write setup to clock high
tWS 1.7–1.7– ns 6,7
Chip select setup to clock high
tCSS 1.7–1.7– ns 6,8
Address hold from clock high
tAH 0.7–0.7– ns 6
Data hold from clock high
tDH 0.7–0.7– ns 6
Write hold from clock high
tWH 0.7–0.7– ns 6,7
Chip select hold from clock high
tCSH 0.7–0.7– ns 6,8
Clock enable
setup to clock high
tCENS 1.7–1.7– ns 6
Clock enable hold from clock high
tCENH 0.7–0.7– ns 6
ADV/LD
setup to clock high
tADVS 1.7–1.7– ns 6
ADV/LD
hold from clock high
tADVH 0.7–0.7– ns 6
1 Refer to “notes” on page 16.
Description Conditions Symbol Min Max Units
Current during Snooze Mode ZZ > VIH ISB2 30 mA
ZZ active to input ignored tPDS 2cycle
ZZ inactive to input sampled tPUS 2cycle
ZZ active to SNOOZE current tZZI 2cycle
ZZ inactive to exit SNOOZE current tRZZI 0
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Key to switching waveforms
Timing waveform of read cycle
Undefined
Falling inputRising input don’t care
tCH tCYC
tCL
tAS
CLK
CEN
R/W
tCEH
A1 A2 A3
Address
tAH
tCES
tWS tWH
CE0,CE2
tADVS
tCSH
Dout
CE1
tADVH
tOE
tLZOE
tHZOE
Q(A1)
Q(A2Y‘01)
Q(A2) Q(A3)
tHLZC
OE
ADV/LD
BWn
tWS tWH
Q(A2Y‘10)
Q(A2Y‘11)
Read
Q(A1)
DSEL Read
Q(A2)
Continue
Read
Q(A2Y‘01)
Continue
Read
Q(A2Y‘10)
Continue
Read
Q(A2Y‘11)
Inhibit
Clock
Read
Q(A3)
Continue
Read
Q(A3Y‘01)
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Timing waveform of write cycle
tCH tCYC
tCL
tAS
CLK
CEN
R/W
tCEH
A1 A2 A3
Address
tAH
tCES
CE0,CE2
tADVS
tCSH
Din
CE1
tADVH
tHZOE
D(A1) D(A2) D(A3)
tDS
OE
ADV/LD
tDH
Q(n-2)
Dout
BWn
Q(n-1)
D(A2Y‘01) D(A2Y‘10) D(A2Y‘11)
Write
D(A1)
DSEL Write
D(A2)
Continue
Write
D(A2Y‘01)
Continue
Write
D(A2Y‘10)
Continue
Write
D(A2Y‘11)
Inhibit
Clock
Write
D(A3)
Continue
Write
D(A3Y‘01)
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Timing waveform of read/write cycle
Note: Ý = XOR when LBO = high/no connect. Ý = ADD when LBO = low. BW[a:d] is don’t care.
tCH tCYC
tCL
tCENS
tOH tOE
CLK
CEN
CE0, CE2
ADV/LD
R/W
ADDRESS
D/Q
OE
Command
tHZOE
BWn
A2A1 A3 A5A4
A7
A6
D(A1) D(A5) Q(A6)
D(A2)
D(A2
Ý
01)
Q(A3) Q(A4)
Q(A4
Ý
01
)
tCENH
tDS tDH tLZC
tCD
tHZC
tLZOE
Read
Q(A3) Read
Q(A4)
Burst
Read
Q(A4Ý01)
Write
D(A5)
Read
Q(A6)
Write
D(A7)
DSEL
tCSS
tADVH
tWS tWH
tWS tWH
CE1
Write
D(A1)
Write
D(A2)
tADVS
tCSH
tAS tAH
Burst
Write
D(A2Ý01)
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NOP, stall and deselect cycles
Note: Ý = XOR when LBO = high/no connect; Ý = ADD when LBO = low. OE is low.
CLK
CEN
CE0, CE2
ADV/LD
R/W
Address
D/Q
Command
BWn
A1 A2
Q(A1) D(A2)
Q(A1
Ý
01) Q(A1
Ý
10)
Burst
Q(A1Ý01
)
STALL DSEL Burst
DSEL
Write
D(A2)
Burst
NOP
D(A2Ý01
)
Write
NOP
D(A3)
A3
Read
Q(A1) Burst
Q(A1Ý10
)
Burst
D(A2Ý10)
CE1
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Timing waveform of snooze mode
AC test conditions
CLK
All inputs
ZZ
tZZI
Isupply
(except ZZ)
Dout
tPUS
ZZ recovery cycle
ISB2
tRZZI
ZZ setup cycle
Deselect or Read Only Deselect or Read Only
Normal
operation
Cycle
High-Z
Z0=50Ω
Dout
50Ω
VL=1.5V
Figure B: Output load (A)
30 pF*
Figure A: Input waveform
10%
90%
GND
90%
10%
+3.0V
• 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.
353
Ω/
1538
Ω
5 pF*
319
Ω
/1667
Ω
D
OUT
GND
Figure C: Output load(B)
*including scope
and jig capacitance
Thevenin equivalent:
+3.3V for 3.3V I/O;
/+2.5V for 2.5V I/O
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Notes
1 For test conditions, see AC Test Conditions, Figures A, B, C.
2 This parameter measured with output load condition in Figure C
3 This parameter is sampled and not 100% tested.
4t
HZOE is less than tLZOE; and tHZC is less than tLZC at any given temper-
ature and voltage.
5tHZCN is a‘no load’ parameter to indicate exactly when SRAM outputs
have stopped driving.
6I
CC given with no output loading. ICC increases with faster cycle times
and greater output loading.
7 Transitions are measured ±500 mV from steady state voltage. Output
loading specified with CL = 5 pF as in Figure C.
8t
CH measured as high above VIH, and tCL measured as low below VIL
9 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.
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Package Dimensions
He E
Hd
D
b
e
TQFP
Min Max
A1 0.05 0.15
A2 1.35 1.45
b 0.22 0.38
c 0.09 0.20
D 13.80 14.20
E 19.80 20.20
e 0.65 nominal
Hd 15.80 16.20
He 21.80 22.20
L 0.45 0.75
L1 1.00 nominal
α0° 7°
Dimensions in millimeters
100-pin quad flat pack (TQFP)
α
A1
A2
L1
L
c
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Ordering information
Note: Add suffix ‘N’ to he above part numbers for Lead Free Parts (Ex. AS7C33256NTD32A-166TQCN)
Part numbering guide
1.Alliance Semiconductor SRAM prefix
2.Operating voltage: 33 = 3.3V
3.Organization:
256
=
256
K
4.NTDTM = No Turn-around Delay. Pipelined mode.
5.Organization: 32 = x32; 36 = x36
6.Production version: A = first production version
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
Package Width 166 MHz 133 MHz
TQFP ×32 AS7C33256NTD32A-166TQC AS7C33256NTD32A-133TQC
TQFP ×32 AS7C33256NTD32A-166TQI AS7C33256NTD32A-133TQI
TQFP ×36 AS7C33256NTD36A-166TQC AS7C33256NTD36A-133TQC
TQFP ×36 AS7C33256NTD36A-166TQI AS7C33256NTD36A-133TQI
AS7C 33 256 NTD 32/36 A–XXX TQ C/I X
1
23
45678
910
AS7C33256NTD32A
AS7C33256NTD36A
®
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Part Number:AS7C33256NTD36A
Document Version: v. 2.1
®
AS7C33256NTD32A
