AS7C251MNTD32A-167BCN [ALSC]
ZBT SRAM, 1MX32, 7.5ns, CMOS, PBGA165, LEAD-FREE, BGA-165;型号: | AS7C251MNTD32A-167BCN |
厂家: | ALLIANCE SEMICONDUCTOR CORPORATION |
描述: | ZBT SRAM, 1MX32, 7.5ns, CMOS, PBGA165, LEAD-FREE, BGA-165 时钟 ISM频段 静态存储器 内存集成电路 |
文件: | 总22页 (文件大小:453K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
April 2004
AS7C251MNTD32A
AS7C251MNTD36A
®
2.5V 1M × 32/36 SRAM with NTDTM
Features
• Common data inputs and data outputs
• Organization: 1,048,576 words × 32 or 36 bits
• NTD™1 architecture for efficient bus operation
• Fast clock speeds to 200 MHz in LVTTL/LVCMOS
• Fast clock to data access: 3.1/3.4/3.8 ns
• Fast OE access time: 3.1/3.4/3.8 ns
• Asynchronous output enable control
• Available in 100-pin TQFP and 165-ball BGA packages
• Byte write enables
• Clock enable for operation hold
• Multiple chip enables for easy expansion
• 2.5V core power supply
• Fully synchronous operation
• Flow-through or pipelined mode
• Self-timed write cycles
• Interleaved or linear burst modes
• Snooze mode for standby operation
• Boundary scan using IEEE 1149.1 JTAG function
1. NTD™ is a trademark of Alliance Semiconductor Corporation. All trade-
marks mentioned in this document are the property of their respective owners.
Logic block diagram
20
20
Q
A[19:0]
D
Address
register
Burst logic
CLK
D
Q
CE0
CE1
CE2
Write delay
addr. registers
20
CLK
R/W
BWa
Control
logic
CLK
BWb
BWc
BWd
ADV / LD
FT
1M x 32/36
SRAM
LBO
ZZ
CLK
Array
32/36
32/36
DQ[a,b,c,d]
Data
Input
Register
D
Q
32/36
32/36
CLK
32/36
CLK
CEN
CLK
Output
Register
OE
32/36
OE
DQ[a,b,c,d]
Selection guide
-200
5
-167
6
-133
7.5
Units
ns
Minimum cycle time
Maximum pipelined clock frequency
Maximum pipelined clock access time
Maximum operating current
200
3.1
400
120
70
167
3.4
350
110
70
133
3.8
MHz
ns
325
100
70
mA
mA
mA
Maximum standby current
Maximum CMOS standby current (DC)
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P. 1 of 22
Copyright © Alliance Semiconductor. All rights reserved.
AS7C251MNTD32A
AS7C251MNTD36A
®
Pin and ball assignment
100-pin TQFP - top view
1
2
3
4
5
6
7
8
9
NC/DQPc
DQc0
DQPb/NC
DQb7
DQb6
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
DQc1
V
V
DDQ
DDQ
V
V
SSQ
SSQ
DQc2
DQc3
DQc4
DQc5
DQb5
DQb4
DQb3
DQb2
V
V
10
11
12
SSQ
SSQ
V
V
DDQ
DDQ
DQc6
DQc7
FT
DQb1
DQb0
13
14
15
16
17
18
19
20
21
22
23
24
25
26
V
SS
TQFP 14 x 20mm
V
NC
DD
NC
V
DD
V
ZZ
DQa7
DQa6
SS
DQd0
DQd1
V
V
DDQ
DDQ
V
V
SSQ
SSQ
DQd2
DQd3
DQd4
DQd5
DQa5
DQa4
DQa3
DQa2
V
V
V
SSQ
SSQ
DDQ
V
27
28
29
30
DDQ
DQd6
DQd7
NC/DQPd
DQa1
DQa0
DQPa/NC
Note: For pins 1, 30, 51, and 80, NC applies to the x32 configuration. DQPn applies to the x36 configuration.
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P. 2 of 22
AS7C251MNTD32A
AS7C251MNTD36A
®
165-ball BGA - top view for 1M X 36
1
2
3
4
5
6
7
8
9
10
11
NC
A
CE0
BWc
BWb
CE2
CEN
ADV/LD
A
A
NC
A
B
C
D
E
F
NC
DQPc
DQc
DQc
DQc
DQc
FT
A
CE1
BWd
BWa
CLK
R/W
OE
A
A
NC
DQPb
DQb
DQb
DQb
DQb
ZZ
NC
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
NC
DDQ
DDQ
DDQ
DDQ
DDQ
SS
DD
DD
DD
DD
DD
DD
DD
DD
DD
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
SS
DD
DD
DD
DD
DD
DD
DD
DD
DD
DDQ
DDQ
DDQ
DDQ
DDQ
DQc
DQc
DQc
DQc
NC
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
DQb
DQb
DQb
DQb
NC
G
H
J
NC
NC
DQd
DQd
DQd
DQd
DQPd
NC
DQd
DQd
DQd
DQd
NC
V
V
DQa
DQa
DQa
DQa
NC
DQa
DQa
DQa
DQa
DQPa
NC
DDQ
DDQ
DDQ
DDQ
DDQ
DDQ
DDQ
DDQ
V
V
V
V
V
V
V
V
K
L
M
N
P
V
NC
TDI
NC
NC
V
SS
DDQ
SS
DDQ
1
NC
A
A
A
A1
TDO
TCK
A
A
A
A
1
LBO
A
A
TMS
A0
A
A
A
R
1 A0 and A1 are the two least significant bits (LSB) of the address field and set the internal burst counter if burst is desired.
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P. 3 of 22
AS7C251MNTD32A
AS7C251MNTD36A
®
Functional description
The AS7C251MNTD32A/36A family is a high performance CMOS 32 Mbit synchronous Static Random Access Memory (SRAM)
organized as 1,048,576 words × 32 or 36 bits and incorporates a LATE LATE Write.
This variation of the 32Mb+ synchronous 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 AS7C251MNTD32A/36A operates with a 2.5V ± 5% power supply for the device core (VDD). These devices are available in a 100-pin
TQFP and 165-ball BGA packages.
Capacitance
Parameter
Symbol
Test conditions
V = 0V
Min
Max
Unit
pF
Input capacitance
I/O capacitance
C
-
-
5
7
IN
in
C
V = V = 0V
pF
I/O
in
out
TQFP and BGA thermal resistance
Description
Conditions
Symbol
Typical
40
Units
°C/W
°C/W
1–layer
4–layer
θJA
θJA
Thermal resistance
(junction to ambient)1
Test conditions follow standard test methods
and procedures for measuring thermal
impedance, per EIA/JESD51
22
Thermal resistance
(junction to top of case)1
θJC
8
°C/W
1 This parameter is sampled
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P. 4 of 22
AS7C251MNTD32A
AS7C251MNTD36A
®
Signal descriptions
Signal
CLK
I/O Properties Description
I
I
I
CLOCK Clock. All inputs except OE, FT, LBO, and ZZ are synchronous to this clock.
CEN
SYNC
SYNC
SYNC
Clock enable. When de-asserted high, the clock input signal is masked.
Address. Sampled when all chip enables are active and ADV/LD is asserted.
Data. Driven as output when the chip is enabled and OE is active.
A, A0, A1
DQ[a,b,c,d] I/O
CE0, CE1,
CE2
Synchronous chip enables. Sampled at the rising edge of CLK, when ADV/LD is asserted.
Are ignored when ADV/LD is high.
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.
ADV/LD
R/W
I
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.
SYNC
SYNC
Byte write enables. Used to control write on individual bytes. Sampled along with WRITE
command and BURST WRITE.
BW[a,b,c,d]
OE
I
I
I
ASYNC Asynchronous output enable. I/O pins are not driven when OE is inactive.
Selects Burst mode. When tied to VDD or left floating, device follows interleaved Burst order. When
STATIC
LBO
driven Low, device follows linear Burst order. This signal is internally pulled High.
Selects Pipeline or Flow-through mode. When tied to VDD or left floating, enables Pipeline mode.
STATIC
FT
I
When driven Low, enables single register Flow-through mode. This signal is internally pulled High.
Serial data-out to the JTAG circuit. Delivers data on the negative edge of TCK. (BGA
TDO
TDI
O
I
SYNC
only)
SYNC
Serial data-in to the JTAG circuit. Sampled on the rising edge of TCK. (BGA only)
This pin controls the Test Access Port state machine. Sampled on the rising edge of TCK.
(BGA only)
TMS
I
SYNC
Serial data-out to the JTAG circuit. Delivers data on the negative edge of TCK. (BGA
only)
TCK
O
SYNC
ZZ
I
-
ASYNC Snooze. Places device in low power mode; data is retained. Connect to GND if unused.
No connects.
NC
-
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AS7C251MNTD32A
AS7C251MNTD36A
®
Burst order
Interleaved burst order LBO = 1
A1 A0 A1 A0 A1 A0 A1 A0
Linear burst order LBO = 0
A1 A0 A1 A0 A1 A0 A1 A0
Starting address
First increment
0 0
0 1
0 1
0 0
1 1
1 0
1 0
1 1
0 0
0 1
1 1
1 0
0 1
0 0
Starting Address
First increment
0 0
0 1
0 1
1 0
1 1
0 0
1 0
1 1
0 0
0 1
1 1
0 0
0 1
1 0
Second increment 1 0
Third increment 1 1
Second increment 1 0
Third increment
1 1
Synchronous truth table[5,6,7,8,9]
Address
CE0 CE1 CE2 ADV/LD R/W
BWn
X
OE CEN source
CLK
Operation
DQ
High-Z
High-Z
High-Z
High-Z
Q
Notes
H
X
X
X
L
X
X
L
X
H
X
X
L
L
L
L
H
L
H
L
H
L
H
L
X
X
X
X
H
X
H
X
L
X
X
X
X
L
L
L
L
L
L
L
L
L
L
L
L
NA
NA
NA
NA
L to H
L to H
L to H
L to H
DESELECT Cycle
DESELECT Cycle
DESELECT Cycle
X
X
X
H
X
H
X
H
X
H
X
CONTINUE DESELECT Cycle
READ Cycle (Begin Burst)
READ Cycle (Continue Burst)
1
X
External L to H
Next L to H
X
L
X
L
X
L
Q
1,10
2
X
H
H
X
X
X
External L to H NOP/DUMMY READ (Begin Burst) High-Z
X
L
X
L
X
Next L to H DUMMY READ (Continue Burst) High-Z 1,2,10
L
External L to H
WRITE CYCLE (Begin Burst)
D
D
3
X
L
X
L
X
L
L
Next L to H WRITE CYCLE (Continue Burst)
1,3,10
H
External L to H NOP/WRITE ABORT (Begin Burst) High-Z 2,3
1,2,3,
X
X
X
H
X
H
X
X
L
Next L to H WRITE ABORT (Continue Burst)
High-Z
10
X
X
X
X
X
X
H
Current L to H
INHIBIT CLOCK
-
4
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.
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AS7C251MNTD32A
AS7C251MNTD36A
®
State diagram for NTD SRAM
Burst
Read
Burst
Read
Read
Burst
Read
Dsel
Dsel
Burst
Burst
Write
Burst
Write
Burst
Write
Write
Absolute maximum ratings
Parameter
Power supply voltage relative to GND
Input voltage relative to GND (input pins)
Input voltage relative to GND (I/O pins)
Power dissipation
Symbol
Min
Max
+3.6
Unit
V
VDD, VDDQ
VIN
–0.3
–0.3
–0.3
–
VDD + 0.3
VDDQ + 0.3
1.8
V
VIN
V
Pd
W
Short circuit output current
IOUT
–
20
mA
oC
oC
oC
Storage temperature (TQFP)
Storage temperature (BGA)
Tstg (TQFP)
Tstg (BGA)
Tbias
–65
–65
–65
+150
+125
Temperature under bias
+135
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
Parameter
Supply voltage for inputs
Supply voltage for I/O
Ground supply
Symbol
VDD
Min
2.375
2.375
0
Nominal
Max
2.625
2.625
0
Unit
V
2.5
2.5
0
VDDQ
Vss
V
V
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P. 7 of 22
AS7C251MNTD32A
AS7C251MNTD36A
®
DC electrical characteristics
Parameter
Input leakage current
Output leakage current
Sym
|ILI|
Conditions
VDD = Max, OV < VIN < VDD
OE ≥ VIH, VDD = Max, OV < VOUT < VDDQ
Address and control pins
I/O pins
Min
-2
Max
Unit
µA
µA
V
2
|ILO
|
-2
2
VDD+0.3
VDDQ+0.3
0.7
1.7
1.7
-0.3*
-0.3*
1.7
–
Input high (logic 1) voltage
Input low (logic 0) voltage
VIH
V
Address and control pins
I/O pins
V
VIL
0.7
V
Output high voltage
Output low voltage
VOH
VOL
IOH = –4 mA, VDDQ = 2.375V
IOL = 8 mA, VDDQ = 2.625V
–
V
0.7
V
*VIL min = -1.5 for pulse width less than 0.2 X tCYC
IDD operating conditions and maximum limits
Parameter
Sym
Test conditions
-200
-167
-133
Unit
Operating power supply
current (pipelined mode)
I
400
350
325
mA
1
CC
CE = V , CE = V , CE = V ,
0
IL
1
IH
2
IL
Operating power supply
I
f = f
I
= 0 mA
CC
max, out
1
current (flow-through
325
280
260
mA
(FT)
mode)
I
Deselected, f = f
ZZ < V
IL
120
70
110
70
100
70
SB
max,
Deselected, f = 0, ZZ < 0.2V
I
SB1
Standby power supply
current
all V ≤ 0.2V or ≥ V - 0.2V
IN
DD
mA
Deselected, f = f
,
Max
I
ZZ ≥ V - 0.2V,
60
60
60
SB2
DD
all V ≤ V or ≥ V
IN
IL
IH
1 I given with no output loading. I increases with faster cycle times and greater output loading.
CC
CC
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P. 8 of 22
AS7C251MNTD32A
AS7C251MNTD36A
®
Timing characteristics over operating range
-200
-167
-133
1
Parameter
Sym
Unit Notes
Min
Max
200
–
Min
Max
167
–
Min
Max
Clock frequency
F
t
–
–
–
133 MHz
MAX
CYC
Cycle time (pipelined mode)
Cycle time (flow-through mode)
Clock access time (pipelined mode)
Clock access time (flow-through mode)
Output enable low to data valid
Clock high to output low Z
5
6
7.5
12
–
–
–
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
t
7.5
–
–
8.5
–
–
CYCF
t
3.1
6.5
3.1
–
3.4
7.5
3.4
–
3.8
10
3.8
–
CD
t
–
–
–
CDF
t
–
–
–
OE
t
0
0
0
2,3,4
2
LZC
Data output invalid from clock high (pipelined mode)
t
1.5
3.0
0
–
1.5
3.0
0
–
1.5
3.0
0
–
OH
Data Output invalid from clock high (flow-through mode) t
–
–
–
2
OHF
Output enable low to output low Z
Output enable high to output high Z
Clock high to output high Z
Output enable high to invalid output
Clock high pulse width
t
–
–
–
2,3,4
2,3,4
2,3,4
LZOE
HZOE
t
–
3.0
3.0
–
–
3.4
3.4
–
–
3.8
3.8
–
t
–
–
–
HZC
t
0
0
0
OHOE
t
2.0
2.0
1.4
1.4
1.4
1.4
0.4
0.4
0.4
0.4
1.4
0.4
1.4
0.4
–
2.4
2.3
1.5
1.5
1.5
1.5
0.5
0.5
0.5
0.5
1.5
0.5
1.5
0.5
–
2.4
2.4
1.5
1.5
1.5
1.5
0.5
0.5
0.5
0.5
1.5
0.5
1.5
0.5
–
5
5
CH
Clock low pulse width
t
t
t
–
–
–
CL
AS
DS
Address and Control setup to clock high
Data setup to clock high
–
–
–
6
–
–
–
6
Write setup to clock high
t
–
–
–
6, 7
6, 8
6
WS
Chip select setup to clock high
Address hold from clock high
Data hold from clock high
t
–
–
–
CSS
t
–
–
–
AH
DH
WH
t
–
–
–
6
Write hold from clock high
Chip select hold from clock high
Clock enable setup to clock high
Clock enable hold from clock high
ADV setup to clock high
t
–
–
–
6, 7
6, 8
6
t
–
–
–
CSH
t
–
–
–
CENS
CENH
ADVS
ADVH
t
t
–
–
–
6
–
–
–
6
ADV hold from clock high
t
–
–
–
6
1 See “Notes” on page 19
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P. 9 of 22
AS7C251MNTD32A
AS7C251MNTD36A
®
IEEE 1149.1 serial boundary scan (JTAG)
The SRAM incorporates a serial boundary scan test access port (TAP). The port operates in accordance with IEEE Standard
1149.1-1990. The SRAM contains a TAP controller, instruction register, boundary scan register, bypass register, and ID
register.
Disabling the JTAG feature
If the JTAG function is not being implemented, TCK should be grounded to avoid mid-level input. At power-up, the device
will come up in a reset state which will not interfere with the operation of the device.
TAP controller state diagram
TAP controller block diagram
TEST-LOGIC
RESET
1
0
0
1
SELECT
DR-SCAN
1
1
SELECT
IR-SCAN
RUN-TEST/
IDLE
Bypass Register
0
Selection
Circuitry
Selection
Circuitry
2
1 0
0
0
Instruction Register
TDI
TDO
1
1
.
. .
2
3130 29
1 0
CAPTURE-DR
0
CAPTURE-IR
0
Identification Register
.
. . . .
2
x
1 0
1
Boundary Scan Register
SHIFT-DR
1
0
SHIFT-IR
1
0
1
1
EXIT1-IR
0
EXIT1-DR
0
TCK
TMS
TAP Controller
PAUSE-IR
1
PAUSE-DR
1
0
0
1
x = 75
0
0
EXIT2-DR
1
EXIT2-IR
1
UPDATE-IR
UPDATE-DR
1
0
1
0
Note: The 0 or 1 next to each state represents the value of TMS at the rising edge of TCK.
Test access port (TAP)
Test clock (TCK)
The test clock is used only with the TAP controller. All inputs are captured on the rising edge of TCK. All outputs are driven
from the falling edge of TCK.
Test mode select (TMS)
The TAP controller receives commands from TMS input. It is sampled on the rising edge of TCK. You can leave this pin/ball
unconnected if the TAP is not used. The pin/ball is pulled up internally, resulting in a logic high level.
Test data-in (TDI)
The TDI pin/ball serially inputs information into the registers and can be connected to the input of any of the registers. The
register between TDI and TDO is chosen by the instruction that is loaded into the TAP instruction register. For information on
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loading the instruction register, see the TAP Controller State Diagram. TDI is internally pulled up and can be unconnected if
the TAP is unused in an application. TDI is connected to the most significant bit (MSB) of any register.
Test data-out (TDO)
The TDO output pin/ball serially clocks data-out from the registers. The output is active depending upon the current state of
the TAP state machine. The output changes on the falling edge of TCK. TDO is connected to the least significant bit (LSB) of
any register. (See the TAP Controller State Diagram.)
Performing a TAP RESET
You can perform a RESET by forcing TMS high (V ) for five rising edges of TCK. This RESET does not affect the
DD
operation of the SRAM and can be performed while the SRAM is operating.
At power-up, the TAP is reset internally to ensure that TDO comes up in a high-Z state.
TAP registers
Registers are connected between the TDI and TDO pins/balls. They allow data to be scanned into and out of the SRAM test
circuitry. Only one register can be selected at a time through the instruction register. Data is serially loaded into the TDI pin/
ball on the rising edge of TCK. Data is output on the TDO pin/ball on the falling edge of TCK.
Instruction register
You can serially load three-bit instructions into the instruction register. The register is loaded when it is placed between the
TDI and TDO pins/balls as shown in the TAP Controller Block Diagram. The instruction register is loaded with the IDCODE
instruction at power up and also if the controller is placed in a reset state, as described in the previous section.
When the TAP controller is in the Capture-IR state, the two least significant bits are loaded with a binary “01” pattern to allow
for fault isolation of the board-level series test data path.
Bypass register
To save time when serially shifting data through registers, it is sometimes advantageous to skip certain chips. The bypass
register is a single-bit register that can be placed between the TDI and TDO pins/balls. This allows data to be shifted through
the SRAM with minimal delay. The bypass register is set low (Vss) when the BYPASS instruction is executed.
Boundary scan register
The boundary scan register is connected to all the input and bidirectional pins/balls on the SRAM. The chip has a 76-bit-long
register.
The boundary scan register is loaded with the contents of the RAM I/O ring when the TAP controller is in the Capture-DR
state and is then placed between the TDI and TDO pins/balls when the controller is moved to the Shift-DR state. The
EXTEST, SAMPLE/PRELOAD, and SAMPLE Z instructions can be used to capture the contents of the I/O ring.
The boundary scan order table shows the order in which the bits are connected. Each bit corresponds to one of the bumps on
the SRAM package. The most significant bit (MSB) of the register is connected to TDI, and the least significant bit (LSB) is
connected to TDO.
Identification (ID) register
The ID register has a vendor code and other information described in the Identification Register Definitions table. The ID
register is loaded with a vendor-specific, 32-bit code during the Capture-DR state when the IDCODE command is loaded in
the instruction register. The IDCODE is hardwired into the SRAM and can be shifted out when the TAP controller is in the
Shift-DR state.
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TAP instruction set
Eight different instructions are possible with the 3-bit instruction register. All combinations are listed in the Instruction Codes
table. One of these instructions is reserved and should not be used.
Instructions are loaded into the TAP controller during the Shift-IR state when the instruction register is placed between TDI
and TDO. During this state, instructions are shifted through the instruction register through the TDI and TDO pins/balls. To
execute the instruction once it is shifted in, the TAP controller needs to be moved into the Update-IR state.
EXTEST
EXTEST is a mandatory 1149.1 instruction which is to be executed whenever the instruction register is loaded with all 0s.
EXTEST is not implemented in this SRAM TAP controller, and therefore this device is not compliant to 1149.1.
The TAP controller does recognize an all-0 instruction. When an EXTEST instruction is loaded into the instruction register,
the SRAM responds as if a SAMPLE/PRELOAD instruction has been loaded. There is one difference between the two
instructions, unlike the SAMPLE/PRELOAD instruction, EXTEST places the SRAM outputs in a High-Z state.
IDCODE
The IDCODE instruction is loaded into the instruction register upon power-up or whenever the TAP controller is given a test
logic reset state. The IDCODE instruction causes a vendor-specific, 32-bit code to be loaded into the identification register. It
also places the identification register between the TDI and TDO pins/balls and allows the IDCODE to be shifted out of the
device when the TAP controller enters the Shift-DR state.
SAMPLE Z
The SAMPLE Z instruction causes the boundary scan register to be connected between the TDI and TDO pins/balls when the
TAP controller is in a Shift-DR state. It also places all SRAM outputs into a high-Z state.
SAMPLE/PRELOAD
SAMPLE/PRELOAD is a Standard 1149.1 mandatory public instruction. When the SAMPLE/PRELOAD instruction is
loaded in the Instruction Register, moving the TAP controller into the Capture-DR state loads the data in the RAM’s input and
I/O buffers into the Boundary Scan Register. Boundary Scan Register locations are not associated with an input or I/O pin, and
are loaded with the default state identified in the Boundary Scan Chain table at the end of this section of the datasheet.Because
the RAM clock is independent from the TAP clock (TCK) it is possible for the TAP to attempt to capture the I/O ring contents
while the input buffers are in transition (i.e. in a metastable state). Although allowing the TAP to sample metastable inputs will
not harm the device, repeatable results cannot be accepted. RAM input signals must be stabilized for long enough to meet the
TAP’s input data capture set-up plus hold time (tCS plus tCH). The RAM’s clock inputs need not be paused for any other TAP
operation except capturing the I/O ring contents into the boundary Scan Register. Moving the controller to Shift-DR state then
places the boundary scan register between the TDI and TDO pins.
BYPASS
The advantage of the BYPASS instruction is that it shortens the boundary scan path when multiple devices are connected
together on a board. When the BYPASS instruction is loaded in the instruction register and the TAP is placed in a Shift-DR
state, the bypass register is placed between TDI and TDO.
RESERVED
Do not use a reserved instruction. These instructions are not implemented but are reserved for future use.
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TAP timing diagram
1
2
3
4
5
6
Test Clock
(TCK)
t
t
t
THTH
THTL
TLTH
Test Mode Select
(TMS)
t
t
MVTH THMX
Test Data-In
(TDI)
t
TLOV
t
t
DVTH
THDX
t
TLOX
Test Data-Out
(TDO)
Undefined
Don’t care
TAP AC electrical characteristics
o
o
For notes 1 and 2, +10 C ≤ T ≤ +110 C and +2.4V ≤ V ≤ +2.6V.
J
DD
Description
Symbol
Min Max Units
Clock
Clock cycle time
Clock frequency
Clock high time
Clock low time
Output Times
tTHTH
fTF
tTHTL
tTLTH
50
ns
MHz
ns
20
10
20
20
ns
TCK low to TDO unknown
TCK low to TDO valid
TDI valid to TCK high
TCK high to TDI invalid
Setup Times
tTLOX
tTLOV
tDVTH
tTHDX
0
ns
ns
ns
ns
5
5
TMS setup
tMVTH
tCS1
5
5
ns
ns
Capture setup
Hold Times
TMS hold
tTHMX
tCH1
5
5
ns
ns
Capture hold
1 tCS and tCH refer to the setup and hold time requirements of latching
data from the boundary scan register.
2 Test conditions are specified using the load in the figure TAP AC output
load equivalent.
TAP AC test conditions
TAP AC output load equivalent
1.25V
Input pulse levels. . . . . . . . . . . . . . . Vss to 2.5V
Input rise and fall times. . . . . . . . . . . . . .1 ns
Input timing reference levels. . . . . . . . . . 1.25V
Output reference levels . . . . . . . . . . . . . 1.25V
Test load termination supply voltage. . . . 1.25V
50Ω
20p
TDO
Z =50
O
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TAP DC electrical characteristics and operating conditions
o
o
(+10 C < T < +110 C and +2.4V < V < +2.6V unless otherwise noted)
J
DD
Description
Input high (logic 1) voltage
Input low (logic 0) voltage
Input leakage current
Conditions
Symbol
VIH
Min
1.7
Max
VDD + 0.3
0.7
Units
V
Notes
1, 2
VIL
-0.3
-5.0
V
1, 2
0V ≤ VIN ≤ VDD
ILI
5.0
µA
Outputs disabled,
0V ≤ VIN ≤ VDDQ(DQx)
Output leakage current
ILO
-5.0
5.0
µA
Output low voltage
Output low voltage
Output high voltage
Output high voltage
IOLC = 100µA
IOLT = 2mA
VOL1
VOL2
VOH1
VOH2
0.2
0.7
V
V
V
V
1
1
1
1
IOHS = -100µA
IOHT = -2mA
2.1
1.7
1. All voltage referenced to V (GND).
SS
t
2. Overshoot: V (AC) ≤ V + 1.5V for t ≤ KHKH/2
IH
DD
t
Undershoot:V (AC) ≥ -0.5 for t ≤ KHKH/2
IL
Power-up: V ≤ +2.6V and V ≤ 2.4V and V ≤ 1.4V for t ≤ 200ms
DDQ
IH
DD
During normal operation, V
must not exceed V . Control input signals (such as LD, R/W, etc.) may not have pulsed
DD
DDQ
widths less than t
(Min) or operate at frequencies exceeding f (Max).
KF
KHKL
Identification register definitions
Instruction field
Revision number (31:28)
Device depth (27:23)
1M x 36
xxxx
Description
Reserved for version number.
xxxxx/xxxxx
xxxxx/xxxxx
xxxxxx
Defines the depth of 1M words.
Device width (22:18)
Defines the width of x32 or x36 bits.
Reserved for future use.
Device ID (17:12)
JEDEC ID code (11:1)
00000110100
1
Allows unique identification of SRAM vendor.
Indicates the presence of an ID register.
ID register presence indicator (0)
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Scan register sizes
Register name
Instruction
Bypass
Bit size
3
1
ID
32
Boundary scan
x36:76
Instruction codes
Instruction
Code
Description
Captures I/O ring contents. Places the boundary scan register between TDI and TDO. Forces all
SRAM outputs to High-Z state. This instruction is not 1149.1-compliant.
EXTEST
IDCODE
000
001
Loads the ID register with the vendor ID code and places the register between TDI and TDO.
This operation does not affect SRAM operations.
Captures I/O ring contents. Places the boundary scan register between TDI and TDO. Forces all
SRAM output drivers to a high-Z state.
SAMPLE Z
RESERVED
010
101
100
Do not use. This instruction is reserved for future use.
SAMPLE/
PRELOAD
Captures I/O ring contents. Places the boundary scan register between TDI and TDO.
Places the bypass register between TDI and TDO. This operation does not affect SRAM
operations.
BYPASS
111, 011, 110
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165-ball BGA boundary scan order (x36)
Bit #s
1
Signal Name
NC
Ball ID
6N
Bit #s
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
Signal Name
CLK
CE2
BWa
BWb
BWc
BWd
CE1
CE0
A
Ball ID
6B
6A
5B
5A
4A
4B
3B
3A
2A
2B
1B
1A
1C
1D
1E
1F
2
A
8P
3
A
8R
4
A
9R
5
A
9P
6
A
10P
10R
11R
11P
11H
11N
11M
11L
11K
11J
7
A
8
A
9
NC
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
ZZ
A
DQPa
DQa
DQa
DQa
DQa
DQa
DQa
DQa
DQa
DQb
DQb
DQb
DQb
DQb
DQb
DQb
DQb
DQPb
NC
NC
NC
DQPc
DQc
DQc
DQc
DQc
DQc
DQc
DQc
DQc
DQd
DQd
DQd
DQd
DQd
DQd
DQd
DQd
DQPd
A
10M
10L
10K
10J
1G
2D
2E
2F
11G
11F
11E
11D
10G
10F
10E
10D
11C
11A
11B
10A
10B
9A
2G
1J
1K
1L
1M
2J
2K
2L
2M
1N
2R
1R
3P
NC
A
A
LBO
A
A
A
9B
A
3R
4R
4P
ADV/LD
OE
8A
A
8B
A
CEN
R/W
7A
A1
6P
7B
A0
6R
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Key to switching waveforms
Rising input
Falling input
Undefined/don’t care
Timing waveform of read/write cycle
tCH tCL
tCYC
CLK
tCENS
tCENH
CEN
CE1
tCSS
tCSH
CE0, CE2
tADVS
tADVH
ADV/LD
tWS
tWH
R/W
tWS
tWH
BWn
tAS
tAH
A3
A4
A5
A6
A7
A1
A2
ADDRESS
tCD
tLZC
tDS tDH
tOH
tOE
tHZC
D/Q
pipelined
D(A5)
Q(A6)
D(A1)
D(A2)
Q(A3)
Q(A4)
Q(A4Ý01)
D(A2Ý01)
tHZOE
tLZOE
OE
D/Q
flow-through
Q(A4Ý01)
D(A5)
Q(A6)
Q(A7)
D(A1)
D(A2)
D(A2Ý01)
Q(A3)
Q(A4)
BURST
READ
Q(A4Ý01)
READ
Q(A3)
DSEL
WRITE
D(A2)
BURST
WRITE
D(A2Ý01)
WRITE
D(A5)
READ
Q(A6)
WRITE
D(A7)
READ
Q(A4)
WRITE
D(A1)
Command
Note: Ý = XOR when LBO = high/no connect. Ý = ADD when LBO = low. BW[a:d] is don’t care.
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NOP, stall and deselect cycles
CLK
CEN
CE1
CE0, CE2
ADV/LD
R/W
BWn
A1
A2
A3
Address
Q(A1Ý01)
Q(A1Ý
10)
D(A2)
Q(A1)
DQ
pipelined
Q(A1Ý01)
Q(A1Ý10)
Q(A1)
D(A2)
DQ
flow-through
Command
BURST
NOP
WRITE
BURST
READ
Q(A1)
STALL
DSEL
BURST
Q(A1 01
BURST
Q(A1 10
BURST WRITE
DSEL D(A2)
NOP
Ý
)
Ý
)
D(A2Ý10)
D(A2Ý0)
D(A3)
Note: Ý = XOR when LBO = high/no connect; Ý = ADD when LBO = low. OE is low.
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AC test conditions
• Output load: For tLZC, tLZOE, tHZOE, and tHZC, see Figure C. For all others, see Figure B.
• Input pulse level: GND to 2.5V. See Figure A.
Thevenin equivalent:
• Input rise and fall time (measured at 0.25V and 2.25V): 2 ns. See Figure A.
• Input and output timing reference levels: 1.25V.
+2.5V
319Ω/1667Ω
50
Ω
DOUT
353 /1538
7
Ω
+
2.5V
VL=VDDQ/2
DOUT
5 pF*
GND
90%
10%
GND
Figure A: Input waveform
90%
Ω
Ω
30 pF*
10%
*including scope
and jig capacitance
Figure B: Output load (A)
Figure C: Output load(B)
Notes
1) For test conditions, see “AC test conditions”, Figures A, B, and C
2) This parameter measured with output load condition in Figure C.
3) This parameter is sampled, but not 100% tested.
4) tHZOE is less than tLZOE, and tHZC is less than tLZC at any given temperature and voltage.
5) tCH is measured high above VIH, and tCL is measured low below VIL
6) 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.
7) Write refers to R/
W
and BW[a,b,c,d]
.
8) Chip select refers to CE0
,
CE1, and CE2.
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Package dimensions
100-pin quad flat pack (TQFP)
TQFP
Hd
D
Min
0.05
1.35
0.22
0.09
Max
0.15
1.45
0.38
0.20
A1
A2
b
b
e
c
D
13.90 14.10
19.90 20.10
0.65 nominal
15.90 16.10
21.90 22.10
He
E
E
e
Hd
He
L
0.45
1.00 nominal
0° 7°
0.75
L1
α
α
Dimensions in millimeters
c
L1
L
A1 A2
165-ball BGA (ball grid array)
Top
Bottom
A1 corner index area
1 2 3 4 5 6 7 8 9 10 11
11 10 9 8 7 6 5 4 3 2 1
A
B
C
A
B
C
A
B
D
E
F
D
E
F
All measurements are in mm.
G
H
J
K
L
M
N
P
R
G
H
J
K
L
M
N
P
R
Min
Typ
1.00
Max
17.10
15.10
A
B
C
D
E
F
16.90
14.90
17.00
14.00
15.00
10.00
0.26
C
1.00
15.00±0.10
A
0.35
1.26
0.45
0.40
0.45
1.46
0.55
G
H
I
D
10.00
E
1.36
15.00±0.10
D
0.50
0.20 Z
G
0.12 Z
H
F
/ 0.50±0.05
Ø
Ø
M Z X Y
M Z
Detail of Solder Ball
Side View
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Ordering information
Package & Width
–200 MHz
–167 MHz
–133 MHz
AS7C251MNTD32A-200TQC
AS7C251MNTD32A-200TQI
AS7C251MNTD36A-200TQC
AS7C251MNTD36A-200TQI
AS7C251MNTD32A-200BC
AS7C251MNTD32A-200BI
AS7C251MNTD36A-200BC
AS7C251MNTD36A-200BI
AS7C251MNTD32A-167TQC
AS7C251MNTD32A-167TQI
AS7C251MNTD36A-167TQC
AS7C251MNTD36A-167TQI
AS7C251MNTD32A-167BC
AS7C251MNTD32A-167BI
AS7C251MNTD36A-167BC
AS7C251MNTD36A-167BI
AS7C251MNTD32A-133TQC
AS7C251MNTD32A-133TQI
AS7C251MNTD36A-133TQC
AS7C251MNTD36A-133TQI
AS7C251MNTD32A-133BC
AS7C251MNTD32A-133BI
AS7C251MNTD36A-133BC
AS7C251MNTD36A-133BI
TQFP x32
TQFP x36
BGA x32
BGA x36
Note:
Add suffix ‘N’ to the above part number for Lead Free Parts (Ex. AS7C251MNTD32A-200TQCN)
Part numbering guide
AS7C
25
1M
NTD
32/36
A
–XXX
TQ or B
C/I
X
1
2
3
4
5
6
7
8
9
10
1. Alliance Semiconductor SRAM prefix
2. Operating voltage: 25 = 2.5V
3. Organization: 1M = 1M
4. NTD™ = No Turn-Around Delay. Pipelined/flow-through mode (each device works in both modes)
5. Organization: 32 = x 32, 36 = x 36
6. Production version: A = first production version
7. Clock speed (MHz)
8. Package type: TQ = TQFP; B = BGA
9. Operating temperature: C = commercial (0° C to 70° C); I = industrial (-40° C to 85° C)
10. N = Lead Free Part
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®
Alliance Semiconductor Corporation
2575, Augustine Drive,
Santa Clara, CA 95054
Tel: 408 - 855 - 4900
Copyright © Alliance Semiconductor
All Rights Reserved
Part Number: AS7C251MNTD32A
AS7C251MNTD36A
Fax: 408 - 855 - 4999
www.alsc.com
Document Version: V 1.0
© 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.
The data contained herein represents Alliance's best data and/or estimates at the time of issuance. Alliance reserves the right to change or correct this
data at any time, without notice. If the product described herein is under development, significant changes to these specifications are possible. The
information in this product data sheet is intended to be general descriptive information for potential customers and users, and is not intended to operate
as, or provide, any guarantee or warrantee to any user or customer. Alliance does not assume any responsibility or liability arising out of the application
or use of any product described herein, and disclaims any express or implied warranties related to the sale and/or use of Alliance products including
liability or warranties related to fitness for a particular purpose, merchantability, or infringement of any intellectual property rights, except as express
agreed to in Alliance's Terms and Conditions of Sale (which are available from Alliance). All sales of Alliance products are made exclusively according
to Alliance's Terms and Conditions of Sale. The purchase of products from Alliance does not convey a license under any patent rights, copyrights; mask
works rights, trademarks, or any other intellectual property rights of Alliance or third parties. Alliance does not authorize its products for use as critical
components in life-supporting systems where a malfunction or failure may reasonably be expected to result in significant injury to the user, and the
inclusion of Alliance products in such life-supporting systems implies that the manufacturer assumes all risk of such use and agrees to indemnify
Alliance against all claims arising from such use.
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