• Byte Write (BW) and/or Global Write (GW) operation
• Internal self-timed write cycle
• Automatic power-down for portable applications
• JEDEC-standard 100-lead TQFP package
-250 -225 -200 -166 -150 -133 Unit
Pipeline
3-1-1-1
3.3 V
2.5 V
Flow
Through
2-1-1-1
3.3 V
2.5 V
t
KQ
tCycle
Curr (x18)
Curr (x32/x36)
Curr (x18)
Curr (x32/x36)
t
KQ
tCycle
Curr (x18)
Curr (x32/x36)
Curr (x18)
Curr (x32/x36)
2.3
4.0
365
430
360
420
6.0
7.0
200
230
200
225
2.5
4.4
335
390
330
380
6.5
7.5
200
230
200
225
3.0
3.5
5.0
6.0
300
265
350
305
295
260
340
295
7.5
8.51010101115ns
8.5
180
180
195
195
180
180
195
195
3.8
6.6
240
280
235
270
180
195
180
195
4.0
7.5nsns
220
245mAmA
215
235mAmA
ns
135
145mAmA
130
145mAmA
250 MHz–133 MHz
2.5 V or 3.3 V V
DD
2.5 V or 3.3 V I/O
cycles can be initiated with either ADSP or ADSC inputs. In
Burst mode, subsequent burst addresses are generated
internally and are controlled by ADV. The burst address
counter may be configured to count in either linear or
interleave order with the Linear Burst Order (LBO) input. The
Burst function need not be used. New addresses can be loaded
on every cycle with no degradation of chip performance.
Flow Through/Pipeline Reads
The function of the Data Output register can be controlled by
the user via the FT mode pin (Pin 14). Holding the FT mode
pin low places the RAM in Flow Through mode, causing
output data to bypass the Data Output Register. Holding FT
high places the RAM in Pipeline mode, activating the risingedge-triggered Data Output Register.
Byte Write and Global Write
Byte write operation is performed by using Byte Write enable
(BW) input combined with one or more individual byte write
signals (Bx). In addition, Global Write (GW) is available for
writing all bytes at one time, regardless of the Byte Write
control inputs.
Sleep Mode
Low power (Sleep mode) is attained through the assertion
(High) of the ZZ signal, or by stopping the clock (CK).
Memory data is retained during Sleep mode.
Core and Interface Voltages
The GS832018/32/36T operates on a 2.5 V or 3.3 V power
supply. All input are 3.3 V and 2.5 V compatible. Separate
output power (V
from the internal circuits and are 3.3 V and 2.5 V compatible.
) pins are used to decouple output noise
DDQ
Functional Description
Applications
The GS832018/32/36T is a 37,748,736-bit high performance
synchronous SRAM with a 2-bit burst address counter.
Although of a type originally developed for Level 2 Cache
applications supporting high performance CPUs, the device
now finds application in synchronous SRAM applications,
ranging from DSP main store to networking chip set support.
Controls
Addresses, data I/Os, chip enables (E1, E2, E3), address burst
control inputs (ADSP, ADSC, ADV), and write control inputs
(Bx, BW, GW) are synchronous and are controlled by a
positive-edge-triggered clock input (CK). Output enable (G)
and power down control (ZZ) are asynchronous inputs. Burst
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
Linear Burst Sequence
I
Mode Pin Functions
Product Preview
GS832018/32/36T-250/225/200/166/150/133
Mode Name
Burst Order ControlLBO
Output Register ControlFT
Power Down ControlZZ
Note:
There is a pull-up device on the and FT pin and a pull-down device on the ZZ pin, so those input pins can be unconnected and the chip will
operate in the default states as specified in the above tables.
Pin
Name
StateFunction
LLinear Burst
HInterleaved Burst
LFlow Through
H or NCPipeline
L or NCActive
H
Standby, IDD = I
SB
Burst Counter Sequences
nterleaved Burst Sequence
A[1:0] A[1:0] A[1:0] A[1:0]
1st address00011011
2nd address01101100
3rd address10110001
1st address00011011
2nd address01001110
3rd address10110001
A[1:0] A[1:0] A[1:0] A[1:0]
4th address11000110
Note: The burst counter wraps to initial state on the 5th clock.
4th address11100100
Note: The burst counter wraps to initial state on the 5th clock.
2.E = T (True) if E2 = 1 and E3 = 0; E = F (False) if E2 = 0 or E3 = 1
3.W = T (True) and F (False) is defined in the Byte Write Truth Table preceding.
4.G is an asynchronous input. G can be driven high at any time to disable active output drivers. G low can only enable active drivers (shown
as “Q” in the Truth Table above).
5.All input combinations shown above are tested and supported. Input combinations shown in gray boxes need not be used to accomplish
basic synchronous or synchronous burst operations and may be avoided for simplicity.
6.Tying ADSP high and ADSC low allows simple non-burst synchronous operations. See BOLD items above.
7.Tying ADSP high and ADV low while using ADSC to load new addresses allows simple burst operations. See ITALIC items above.