512K x 36, 1M x 18
2.5V Synchronous ZBT™ SRAMs
IDT71T75702
2.5V I/O, Burst Counter
OBSOLETE PART
Flow-Through Outputs
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Features
512K x 36, 1M x 18 memory configurations
Supports high performance system speed - 100 MHz
(7.5 ns Clock-to-Data Access)
ZBT
TM
Feature - No dead cycles between write and read cycles
Internally synchronized output buffer enable eliminates the
need to control
OE
Single R/W (READ/WRITE) control pin
4-word burst capability (Interleaved or linear)
Individual byte write (BW
1
-
BW
4
) control (May tie active)
Three chip enables for simple depth expansion
2.5V power supply (±5%)
2.5V (±5%) I/O Supply (V
DDQ
)
Power down controlled by ZZ input
Boundary Scan JTAG Interface (IEEE 1149.1 Compliant)
Packaged in a JEDEC standard 100-pin plastic thin quad
flatpack (TQFP), 119 ball grid array (BGA)
Description
The IDT71T75702/902 are 2.5V high-speed 18,874,368-bit
(18 Megabit) synchronous SRAMs organized as 512K x 36 /1M x 18.
They are designed to eliminate dead bus cycles when turning the bus
around between reads and writes, or writes and reads. Thus they have
been given the name ZBT
TM
, or Zero Bus Turnaround.
Address and control signals are applied to the SRAM during one clock
cycle, and on the next clock cycle the associated data cycle occurs, be
it read or write.
Pin Description Summary
A
0
-A
19
Address Inputs
CE
1
, CE
2
,
CE
2
OE
R/W
CEN
Chip Enables
Output Enable
BW
1
,
BW
2
,
BW
3
,
BW
4
CLK
ADV/LD
LBO
TMS
TDI
TCK
TDO
TRST
ZZ
I/O
0
-I/O
31
, I/O
P1
-I/O
P4
V
DD
, V
DDQ
V
SS
T OR
R F
A D
P E
E D
T N
S
E E
L M IGN
O M S
S
B O DE
O EC
R EW
T N
O
N
Input
Synchronous
Input
Synchronous
Input
Asynchronous
Synchronous
Read/Write Signal
Clock Enable
Input
Input
Synchronous
Individual Byte Write Selects
Clock
Input
Synchronous
N/A
Input
Advance Burst Address/Load New Address
Input
Synchronous
Static
N/A
N/A
N/A
N/A
Asynchronous
Synchronous
Synchronous
Static
Static
Linear/Interleaved Burst Order
Test Mode Select
Test Data Input
Test Clock
Test Data Output
JTAG Reset (Optional)
Sleep Mode
Data Input/Output
Core Power, I/O Power
Ground
Input
Input
Input
Input
Output
Input
Input
I/O
Supply
Supply
The IDT71T75702/902 contain address, data-in and control signal
registers. The outputs are flow-through (no output data register). Output
enable is the only asynchronous signal and can be used to disable the
outputs at any given time.
A Clock Enable (CEN) pin allows operation of the IDT71T75702/902
to be suspended as long as necessary. All synchronous inputs are
ignored when
CEN
is high and the internal device registers will hold their
previous values.
There are three chip enable pins (CE
1
, CE
2
,
CE
2
) that allow the
user to deselect the device when desired. If any one of these three is not
asserted when ADV/LD is low, no new memory operation can be initiated.
However, any pending data transfers (reads or writes) will be completed.
The data bus will tri-state one cycle after the chip is deselected or a write
is initiated.
The IDT71T75702/902 have an on-chip burst counter. In the burst
mode, the IDT71T75702/902 can provide four cycles of data for a single
address presented to the SRAM. The order of the burst sequence is
defined by the
LBO
input pin. The
LBO
pin selects between linear and
interleaved burst sequence. The ADV/LD signal is used to load a new
external address (ADV/LD = LOW) or increment the internal burst counter
(ADV/LD = HIGH).
The IDT71T75702/902 SRAMs utilize IDT’s high-performance
CMOS process, and are packaged in a JEDEC Standard 14mm x 20mm
100-pin plastic thin quad flatpack (TQFP) as well as a 119 ball grid array
(BGA).
1
©2009 Integrated Device Technology, Inc.
FEBRUARY 2009
DSC-5319/09
5319 tbl 01
IDT71T75702, IDT71T75902, 512K x 36, 1M x 18, 2.5V Synchronous ZBT™ SRAMs with
2.5V I/O, Burst Counter and Flow-Through Outputs
Commercial and Industrial Temperature Ranges
Pin Definitions
(1)
Symbol
A
0
-A
19
ADV/
LD
Pin Function
Address Inputs
Advance / Load
I/O
I
I
Active
N/A
N/A
Description
Synchronous Address inputs. The address register is triggered by a combination of the rising edge of
CLK, ADV/
LD
low,
CEN
lo w, and true chip enables.
ADV/
LD
is a synchronous input that is used to load the internal registers with new address and control
when it is sampled low at the rising edge of clock with the chip selected. When ADV/
LD
is low with the
chip deselected, any burst in progress is terminated. When ADV/
LD
is sampled high then the internal
burst counter is advanced for any burst that was in progress. The external addresses are ignored when
ADV/
LD
is sampled high.
R/
W
signal is a synchronous input that identifies whether the current load cycle initiated is a Read or
Write access to the memory array. The data bus activity for the current cycle takes place one clock
cycle later.
R/
W
Read / Write
I
N/A
CEN
Clock Enable
I
LOW Synchronous Clock Enable Input. When
CEN
is sampled high, all other synchronous inputs, including
clock are ignored and outputs remain unchanged. The effect of
CEN
sampled high on the device
outputs is as if the low to high clock transition did not occur. For normal operation,
CEN
must be
sampled low at rising edge of clock.
LOW Synchronous byte write enables. Each 9-bit byte has its own active low byte write enable. On load write
cycles (When R/
W
and ADV/
LD
are sampled low) the appropriate byte write signal (
BW
1
-
BW
4
) must be
valid. The byte write signal must also be valid on each cycle of a burst write. Byte Write signals are
ignored when R/
W
is sampled high. The appropriate byte(s) of data are written into the device one cycle
later.
BW
1
-
BW
4
can all be tied low if always doing write to the entire 36-bit word.
LOW Synchronous active low chip enable.
CE
1
and
CE
2
are used with CE
2
to enable the IDT71T75702/902
(
CE
1
or
CE
2
sampled high or CE
2
sampled low) and ADV/
LD
low at the rising edge of clock, initiates a
deselect cycle. The ZBT
TM
has a one cycle deselect, i.e., the data bus will tri-state one clock cycle after
deselect is initiated.
HIGH Synchronous active high chip enable. CE
2
is used with
CE
1
and
CE
2
to enable the chip. CE
2
has
inverted polarity but otherwise identical to
CE
1
and
CE
2
.
N/A
N/A
This is the clock input to the IDT71T75702/902. Except for
OE
, all timing refe rences for the device are
made with respect to the rising edge of CLK.
Data input/output (I/O) pins. The data input path is registered, triggered by the rising edge of CLK. The
data output path is flow-through (no output register).
BW
1
-
BW
4
Individual Byte
Write Enables
I
CE
1
,
CE
2
Chip Enables
I
CE
2
CLK
I/O
0
-I/O
31
I/O
P1
-I/O
P4
Chip Enable
Clock
Data Input/Output
Linear Burst Order
I
I
I/O
I
LBO
LOW Burst ord er selection input. When
LBO
is high the Interleaved burst sequence is selected. When
LBO
is
low the Linear burst sequence is selected.
LBO
is a static input, and it must not change during device
operation.
LOW Asynchronous output enable.
OE
must be low to read data from the IDT71T75702/902. When
OE
is HIGH
the I/O pins are in a high-impedance state.
OE
does not need to be active ly controlled for read and
write cycles. In normal operation,
OE
can be tied low.
N/A
N/A
N/A
N/A
Gives input command for TAP controller; sampled on rising edge of TCK. This pin has an internal pullup.
Serial input of registers placed between TDI and TDO. Sampled on rising edge of TCK. This pin has an
internal pullup.
Clock input of TAP controller. Each TAP event is clocked. Test inputs are captured on rising edge of
TCK, while test outputs are driven from falling edge of TCK. This pin has an internal pullup.
Serial output of registers placed between TDI and TDO. This output is active d epending on the state of
the TAP controller.
OE
Output Enable
I
TMS
TDI
TCK
TDO
Test Mode Select
Test Data Input
Test Clock
Test Data Output
JTAG Reset
(Optional)
I
I
I
O
TRST
I
Optional asynchronous JTAG reset. Can be used to reset the TAP controller, but not required. JTAG
LOW reset occurs automatically at power up and also resets using TMS and TCK per IEEE 1149.1. If not
used
TRST
can be left floating. This pin has an internal pullup. Only available in BGA package.
Synchronous sleep mode input. ZZ HIGH will gate the CLK internally and power down the
HIGH IDT71T75702/902 to its lowest power consumption level. Data retention is guaranteed in Sleep Mode.
This pin has an internal pulldown.
N/A
N/A
N/A
2.5V core power supply.
2.5V I/O Supply.
Ground.
5319 tbl 02
ZZ
V
DD
V
DDQ
V
SS
NOTE:
Sleep Mode
Power Supply
Power Supply
Ground
I
N/A
N/A
N/A
1. All synchronous inputs must meet specified setup and hold times with respect to CLK.
6.42
2
IDT71T75702, IDT71T75902, 512K x 36, 1M x 18, 2.5V Synchronous ZBT™ SRAMs with
2.5V I/O, Burst Counter and Flow-Through Outputs
Commercial and Industrial Temperature Ranges
Functional Block Diagram 512K x 36
LBO
Address A [0:18]
CE
1
, CE
2
CE
2
R/W
CEN
ADV/LD
BWx
Input Register
DI
DO
D
Q
Control
D
Q
512K x 36 BIT
MEMORY ARRAY
Address
D
Clk
Q
Control Logic
Mux
Clock
Sel
OE
Gate
TMS
TDI
TCK
TRST
(optional)
Data I/O [0:31], I/O P[1:4]
JTAG
TDO
5319 drw 01
,
6.42
3
IDT71T75702, IDT71T75902, 512K x 36, 1M x 18, 2.5V Synchronous ZBT™ SRAMs with
2.5V I/O, Burst Counter and Flow-Through Outputs
Commercial and Industrial Temperature Ranges
Functional Block Diagram 1M x 18
LBO
Address A [0:19]
CE
1
, CE
2
CE
2
R/W
CEN
ADV/LD
BWx
Input Register
DI
DO
D
Q
Control
D
Q
1M x 18 BIT
MEMORY ARRAY
Address
D
Clk
Q
Control Logic
Mux
Clock
Sel
OE
Gate
(optional)
TMS
TDI
TCK
TRST
Data I/O [0:15], I/O P[1:2]
JTAG
TDO
5319 drw 01a
,
Recommended DC Operating
Conditions
Symbol
V
DD
V
DDQ
V
SS
V
IH
V
IH
V
IL
Parameter
Core Supply Voltage
I/O Supply Voltage
Ground
Input High Voltage — Inputs
Input High Voltage — I/O
Input Low Voltage
Min.
2.375
2.375
0
1.7
1.7
-0.3
(1)
Typ.
2.5
2.5
0
____
____
____
Max.
2.625
2.625
0
V
DD
+0.3
V
DDQ
+0.3
(2)
0.7
Unit
V
V
V
V
V
V
5319 tbl 03
NOTE:
1. V
IL
(min.) = –0.8V for pulse width less than t
CYC
/2, once per cycle.
6.42
4
IDT71T75702, IDT71T75902, 512K x 36, 1M x 18, 2.5V Synchronous ZBT™ SRAMs with
2.5V I/O, Burst Counter and Flow-Through Outputs
Commercial and Industrial Temperature Ranges
Recommended Operating
Temperature and Supply Voltage
Grade
Commerical
Industrial
Ambient
Temperature
(1)
0 °C to +70 °C
-40 °C to +85 °C
V
SS
OV
OV
V
DD
2.5V ± 5%
2.5V ± 5%
V
DDQ
2.5V ± 5%
2.5V ± 5%
5319 tbl 05
NOTE:
1. During production testing, the case temperature equals the ambient temperature.
V
DD
V
SS
CLK
R/
W
CEN
OE
ADV/LD
CE
2
BW
4
BW
3
BW
2
BW
1
CE
2
A
7
CE
1
A
18
A
17
Pin Configuration 512K x 36
A
6
100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81
I/O
P3
I/O
16
I/O
17
V
DDQ
V
SS
I/O
18
I/O
19
I/O
20
I/O
21
V
SS
V
DDQ
I/O
22
I/O
23
V
SS
(1)
V
DD
V
DD
(2)
V
SS
I/O
24
I/O
25
V
DDQ
V
SS
I/O
26
I/O
27
I/O
28
I/O
29
V
SS
V
DDQ
I/O
30
I/O
31
I/O
P4
A
8
A
9
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
31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
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
I/O
P2
I/O
15
I/O
14
V
DDQ
V
SS
I/O
13
I/O
12
I/O
11
I/O
10
V
SS
V
DDQ
I/O
9
I/O
8
V
SS
V
SS
(1)
V
DD
ZZ
I/O
7
I/O
6
V
DDQ
V
SS
I/O
5
I/O
4
I/O
3
I/O
2
V
SS
V
DDQ
I/O
1
I/O
0
I/O
P1
5319 drw 02
,
LBO
A
5
A
4
A
3
A
2
A
1
A
0
NC / TDO
(3)
NC / TCK
(3,4)
NC / TMS
(3)
NC / TDI
(3)
V
SS
V
DD
A
10
A
11
A
12
A
13
A
14
A
15
Top View
100 TQFP
NOTES:
1. Pins 14 and 66 do not have to be connected directly to V
SS
as long as the input voltage is
≤
V
IL
.
2. Pin 16 does not have to be connected directly to V
DD
as long as the input voltage is
≥
V
IH
.
3. Pins 38, 39 and 43 will be pulled internally to V
DD
if not actively driven. To disable the TAP controller without interfering with normal operation,
several settings are possible. Pins 38, 39 and 43 could be tied to V
DD
or V
SS
and pin 42 should be left unconnected. Or all JTAG inputs (TMS,
TDI and TCK) pins 38, 39 and 43 could be left unconnected “NC” and the JTAG circuit will remain disabled from power up.
4. Pin 43 is reserved for the 36M address. JTAG is not offered in the 100-pin TQFP package for the 36M ZBT device.
6.42
5
A
16
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