1) The document proposes a heterogeneous 3D DRAM chip design that tightly integrates a small SRAM cache with corresponding DRAM arrays using TSVs (through silicon vias).
2) Integrating SRAM caches with DRAM faces challenges due to DRAM process limitations and TSV area overhead, but the design claims TSVs provide high bandwidth connectivity without large energy costs.
3) Experimental results suggest a 32-entry SRAM row cache integrated onto a 3D DRAM chip via TSVs can improve performance and save dynamic energy compared to a conventional DRAM chip.
Time and Low Power Operation Using Embedded Dram to Gain Cell Data RetentionIJMTST Journal
Logic compatible gain cell (GC)-embedded DRAM (eDRAM) arrays are considered an alternative to SRAM because of their small size, non rationed operation, low static leakage, and two port functionality. But traditional GC-eDRAM implementations require boosted control signals in order to write full voltage levels to the cell to reduce the refresh rate and shorten access times. The boosted levels require an extra power supply or on-chip charge pumps, as well as nontrivial level shifting and toleration of high voltage levels. In this paper, we present a novel, logic compatible, 3T GC-eDRAM bit cell that operates with a single-supply voltage and provides superior write capability to the conventional GC structures. The proposed circuit is demonstrated in 0.25μm CMOS process targeted at low power, energy efficient application.
Time and Low Power Operation Using Embedded Dram to Gain Cell Data RetentionIJMTST Journal
Logic compatible gain cell (GC)-embedded DRAM (eDRAM) arrays are considered an alternative to SRAM because of their small size, non rationed operation, low static leakage, and two port functionality. But traditional GC-eDRAM implementations require boosted control signals in order to write full voltage levels to the cell to reduce the refresh rate and shorten access times. The boosted levels require an extra power supply or on-chip charge pumps, as well as nontrivial level shifting and toleration of high voltage levels. In this paper, we present a novel, logic compatible, 3T GC-eDRAM bit cell that operates with a single-supply voltage and provides superior write capability to the conventional GC structures. The proposed circuit is demonstrated in 0.25μm CMOS process targeted at low power, energy efficient application.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Design and implementation of 4 t, 3t and 3t1d dram cell design on 32 nm techn...VLSICS Design
In this paper average power consumption, write access time, read access time and retention time of dram
cell designs have been analyzed for the nano-meter scale memories. Many modern day processors use
dram cell for on chip data and program memory storage. The major power in dram is the off state leakage
current. Improving on the power efficiency of a dram cell is critical for the improvement in average power
consumption of the overall system. 3T dram cell, 4T dram and 3T1D DRAM cells are designed with the
schematic design technique and their average power consumption are compared using TANNER EDA tool
.average power consumption, write access time, read access time and retention time of 4T, 3T dram and
3T1D DRAM cell are simulated and compared on 32 nm technology
A Comparitive Analysis of Improved 6t Sram Cell With Different Sram CellIJERA Editor
High speed and low power consumption have been the primary issue to design Static Random Access Memory (SRAM), but we are facing new challenges with the scaling of technology. The stability and speed of SRAM are important issues to improve efficiency and performance of the system. Stability of the SRAM depends on the static noise margin (SNM) so the noise margin is also important parameter for the design of memory because the higher noise margin confirms the high speed of the SRAM cell. In this paper, the improved 6T SRAM cell shows maximum reduction in power consumption of 88%, maximum reduction in delay of 64% and maximum SNM of 17% increases compared with 7T SRAM cell.
The current technological revolution around the world has made the world faster with the
advancements in sophisticated computer devices. Computer, as a digital machine, enables people
to work faster than ever before. The memory of this device is a great feature of this digital tool.
RAM, Random Access Memory is the primary tool of data storage that is inserted in the
integrated circuit while data can be accessed in any sequence or randomly. Thus it is termed
RAM or Random Access Memory.
The journey of dynamic and static RAM was initiated in 1960s which can readily
developed in 1970s. Now a days the technology is much more user friendly. RAM is further
divided into three types:
• Dynamic RAM (DRAM)
• Static RAM (SRAM)
• Non-volatile RAM (NVRAM = RAM + Battery)
but we will discuss only first two i.e. (DRAM and SRAM).
Dynamic RAM is the most common memory used now a days. Inside of the RAM chip
there is a memory cell that holds one bit of information and is divided into further two parts: a
transistor and a capacitor. The capacitor holds the bit of information as a state of 0 or 1 and the
transistor acts as a switch that lets the control circuitry on the memory chip that reads the
capacitor or change its state. The capacitor is like a small bucket that stores the electrons in it. To
store 1, bucket gets filled with electrons and to store 0 buckets gets empty. The problem with the
capacitor’s bucket is that it has a leak and in a matter of few seconds a full buckets becomes
empty. Therefore they need to be recharged continuously in order to work properly and because
of this reason it has been given the name Dynamic RAM. This refreshing phenomenon is time
consuming as well.
In static RAM a flip-flop holds each bit of a memory. A flip-flop memory cell takes 4 to
6 transistors along with the wiring. Due to this reason they draws current all the time and gets
warm easily, therefore, they cannot be packed together tightly. They do not require any
refreshing method though, therefore, they are very fast memory chips.
Using CMOS Sub-Micron Technology VLSI Implementation of Low Power, High Speed...VLSICS Design
Abstract This paper deals with the design and analysis of high speed Static Random Access Memory (SRAM) cell and Dynamic Random Access Memory (DRAM) cell to develop low power consumption. SRAM and DRAM cells have been the predominant technologies used to implement memory cells in computer systems, each one having its advantages and shortcomings. SRAM cells are faster and require no refresh since reads are not destructive. In contrast, DRAM cells provide higher density and minimal leakage energy. Here we use 12-transistor SRAM cell built from a simple static latch and tri state inverter. The reading action itself refreshes the content of memory. The SRAM access path is split into two portions: from address input to word line rise (the row decoder) and from word line rise to data output (the read data path). The decoder which constitutes the path from address input to the word line rise is implemented as a binary structure by implementing a multi-stage path. The key to low power operation in the SRAM data path is to reduce the signal swings on the high capacitance nodes like the bit lines and the data lines.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Design and implementation of 4 t, 3t and 3t1d dram cell design on 32 nm techn...VLSICS Design
In this paper average power consumption, write access time, read access time and retention time of dram
cell designs have been analyzed for the nano-meter scale memories. Many modern day processors use
dram cell for on chip data and program memory storage. The major power in dram is the off state leakage
current. Improving on the power efficiency of a dram cell is critical for the improvement in average power
consumption of the overall system. 3T dram cell, 4T dram and 3T1D DRAM cells are designed with the
schematic design technique and their average power consumption are compared using TANNER EDA tool
.average power consumption, write access time, read access time and retention time of 4T, 3T dram and
3T1D DRAM cell are simulated and compared on 32 nm technology
A Comparitive Analysis of Improved 6t Sram Cell With Different Sram CellIJERA Editor
High speed and low power consumption have been the primary issue to design Static Random Access Memory (SRAM), but we are facing new challenges with the scaling of technology. The stability and speed of SRAM are important issues to improve efficiency and performance of the system. Stability of the SRAM depends on the static noise margin (SNM) so the noise margin is also important parameter for the design of memory because the higher noise margin confirms the high speed of the SRAM cell. In this paper, the improved 6T SRAM cell shows maximum reduction in power consumption of 88%, maximum reduction in delay of 64% and maximum SNM of 17% increases compared with 7T SRAM cell.
The current technological revolution around the world has made the world faster with the
advancements in sophisticated computer devices. Computer, as a digital machine, enables people
to work faster than ever before. The memory of this device is a great feature of this digital tool.
RAM, Random Access Memory is the primary tool of data storage that is inserted in the
integrated circuit while data can be accessed in any sequence or randomly. Thus it is termed
RAM or Random Access Memory.
The journey of dynamic and static RAM was initiated in 1960s which can readily
developed in 1970s. Now a days the technology is much more user friendly. RAM is further
divided into three types:
• Dynamic RAM (DRAM)
• Static RAM (SRAM)
• Non-volatile RAM (NVRAM = RAM + Battery)
but we will discuss only first two i.e. (DRAM and SRAM).
Dynamic RAM is the most common memory used now a days. Inside of the RAM chip
there is a memory cell that holds one bit of information and is divided into further two parts: a
transistor and a capacitor. The capacitor holds the bit of information as a state of 0 or 1 and the
transistor acts as a switch that lets the control circuitry on the memory chip that reads the
capacitor or change its state. The capacitor is like a small bucket that stores the electrons in it. To
store 1, bucket gets filled with electrons and to store 0 buckets gets empty. The problem with the
capacitor’s bucket is that it has a leak and in a matter of few seconds a full buckets becomes
empty. Therefore they need to be recharged continuously in order to work properly and because
of this reason it has been given the name Dynamic RAM. This refreshing phenomenon is time
consuming as well.
In static RAM a flip-flop holds each bit of a memory. A flip-flop memory cell takes 4 to
6 transistors along with the wiring. Due to this reason they draws current all the time and gets
warm easily, therefore, they cannot be packed together tightly. They do not require any
refreshing method though, therefore, they are very fast memory chips.
Using CMOS Sub-Micron Technology VLSI Implementation of Low Power, High Speed...VLSICS Design
Abstract This paper deals with the design and analysis of high speed Static Random Access Memory (SRAM) cell and Dynamic Random Access Memory (DRAM) cell to develop low power consumption. SRAM and DRAM cells have been the predominant technologies used to implement memory cells in computer systems, each one having its advantages and shortcomings. SRAM cells are faster and require no refresh since reads are not destructive. In contrast, DRAM cells provide higher density and minimal leakage energy. Here we use 12-transistor SRAM cell built from a simple static latch and tri state inverter. The reading action itself refreshes the content of memory. The SRAM access path is split into two portions: from address input to word line rise (the row decoder) and from word line rise to data output (the read data path). The decoder which constitutes the path from address input to the word line rise is implemented as a binary structure by implementing a multi-stage path. The key to low power operation in the SRAM data path is to reduce the signal swings on the high capacitance nodes like the bit lines and the data lines.
Using CMOS Sub-Micron Technology VLSI Implementation of Low Power, High Spee...VLSICS Design
This paper deals with the design and analysis of high speed Static Random Access Memory (SRAM) cell and Dynamic Random Access Memory (DRAM) cell to develop low power consumption. SRAM and DRAM cells have been the predominant technologies used to implement memory cells in computer systems, each one having its advantages and shortcomings. SRAM cells are faster and require no refresh since reads are not destructive. In contrast, DRAM cells provide higher density and minimal leakage energy. Here we use 12-transistor SRAM cell built from a simple static latch and tri state inverter. The reading action itself refreshes the content of memory. The SRAM access path is split into two portions: from address input to word line rise (the row decoder) and from word line rise to data output (the read data path). The decoder which constitutes the path from address input to the word line rise is implemented as a binary structure by implementing a multi-stage path. The key to low power operation in the SRAM data path is to reduce the signal swings on the high capacitance nodes like the bit lines and the data lines.
DESIGN AND IMPLEMENTATION OF 4T, 3T AND 3T1D DRAM CELL DESIGN ON 32 NM TECHNO...VLSICS Design
In this paper average power consumption, write access time, read access time and retention time of dram cell designs have been analyzed for the nano-meter scale memories. Many modern day processors use dram cell for on chip data and program memory storage. The major power in dram is the off state leakage current. Improving on the power efficiency of a dram cell is critical for the improvement in average power consumption of the overall system. 3T dram cell, 4T dram and 3T1D DRAM cells are designed with the schematic design technique and their average power consumption are compared using TANNER EDA tool .average power consumption, write access time, read access time and retention time of 4T, 3T dram and 3T1D DRAM cell are simulated and compared on 32 nm technology.
Design and Simulation Low power SRAM Circuitsijsrd.com
SRAMs), focusing on optimizing delay and power. As the scaling trends in the speed and power of SRAMs with size and technology and find that the SRAM delay scales as the logarithm of its size as long as the interconnect delay is negligible. Non-scaling of threshold mismatches with process scaling, causes the signal swings in the bitlines and data lines also not to scale, leading to an increase in the relative delay of an SRAM, across technology generations. Appropriate methods for reduction of power consumption were studied such as capacitance reduction, very low operating voltages, DC and AC current reduction and suppression of leakage currents to name a few.. Many of reviewed techniques are applicable to other applications such as ASICs, DSPs, etc. Battery and solar-cell operation requires an operating voltage environment in low voltage area. These conditions demand new design approaches and more sophisticated concepts to retain high device reliability. The proposed techniques (USRS and LPRS) are topology based and hence easier to implement.
250nm Technology Based Low Power SRAM Memoryiosrjce
High integration density, low power and fastperformance are all critical parameters in designing of
memory blocks. Static Random Access Memories (SRAMs)’s focusing on optimizing dynamic power concept of
virtual source transistors is used for removing direct connection between VDD and GND.
Also stacking effect can be reduced by switching off the stacktransistors when the memory is ideal and the
leakage current using SVL techniques This paper discusses the evolution of 9t SRAM circuits in terms of low
power consumption, The whole circuit verification is done on the Tanner tool, Schematic of the
SRAM cell is designed on the S-Edit and net list simulation done by using T-spice and waveforms are analyzed
through the W-edit
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
1. Pragmatic Integration
of an SRAM Row Cache
in
Heterogeneous 3-D
DRAM Architecture
Using TSV
Presented By:
Abhilash.R.A.
2AG10EC001
Under the Guidance of:
Soumya.G
Asst.Professor
AITM,BELAGAVI
2. Random Access Memory
Random access memory is used to store data
bits(writing),as well as their retrieval(reading)
on demand.
RAMs are classified into two main categories.
Dynamic RAMs(DRAM) and Static RAMs
(SRAM).
3. SRAM AND DRAM
SRAM is mainly used for the cache memory in
microprocessors , mainframe computers and
memory in hand held devices due to high
speed and low power consumption.
Due to the low cost and high density, DRAM is
widely used for the main memory in personal
and engineering workstations.
4. Introduction
DRAM industry is facing several imminent
challenges from the limitation posed by
fundamental physics and also from increasing
needs by consumers.
First of all, the DRAM industry is facing a
scaling challenge. As the device feature size
continues to shrink, the capacitance of the
DRAM cell also decreases, at the same time,
the junction leakage current drastically
increases.
5. Introduction
Therefore, maintaining enough capacitance
and reducing leakage current become a
significant challenge, making DRAM feature
size scaling impractical.
In response to the above challenges, the
DRAM industry is undertaking novel
approaches. One innovative solution is to
integrate multiple DRAM die using 3-D die
stacking technology, which increases the
DRAM density without paying the cost of using
a finer lithography technology.
6. Introduction
For example, Samsung has demonstrated an 8
Gb 3-D stacked DDR3 DRAM chip that consists
of four DRAM layers ; in which three layers are
slave layers without any I/O-related circuit while
one layer is the master layer that has shared
I/Os. Such sharing is enabled by TSVs that
allow high bandwidth, low latency, and low
power data communication across layers.
7. What is TSV?
TSVs(through silicon vias) is an essential
element for both wafer –level 3-D integration
and packaging – based 3-D integration ,due to
its short interconnect length,high interconnect
density and small footprint.
8. SPECIALITIES
Proposing a heterogeneous 3-D DRAM chip
design that can better exploit spatial locality by
tightly integrating a small SRAM cache with its
corresponding DRAM array.
Especially, carefully modeling the area and
energy overheads of TSVs and found that
TSVs do not consume much energy while
occupying considerable area when they are
integrated with DRAM.
10. DRAM sub array architecture
DRAM sub array architecture. (a) One DRAM chip, (b) a 256 Mb array block,
and (c)one sub array.
11. Designing TSV-enabled
Heterogeneous DRAM Chips
Unlike a conventional, planar DRAM architecture
described in the previous section, small, fast, and
short TSVs allow one to integrate multiple DRAM
dies vertically providing high bandwidth, low
latency, and low power interconnection among
dies.
Thus, we believe that there will be much space
available for implementing other enhancement
circuits in the logic layer to further improve the
performance and energy efficiency of a DRAM
chip without paying too much additional cost.
Clearly, such a heterogeneous 3-D DRAM chip
will enable many possible, interesting designs in
the future.
12. Design Challenges of an SRAM
Cache in a DRAM Process
First, implementing a row cache requires long, high-
bandwidth wires, which consume significant energy.
Second, unlike a logic process, which has one or two poly
layers with many metal layers, a typical DRAM process has
more poly layers with two metal layers. In other words, with
only two or three metal layers, the DRAM industry used them
to implement all wires such as word lines, bit lines, column
select signals, local I/O lines, and global I/O lines. Thus, to
reasonably implement small SRAM cells in a DRAM die, we
may need more masks than those in a conventional DRAM
process.
Last, a DRAM process is typically optimized for reducing the
leakage current of a storage capacitor. Due to higher
threshold voltage, an SRAM cell implemented on a DRAM
die is much slower unless it is specially manufactured.
13. Designing a Tightly Integrated
SRAM and DRAM Stack with TSVs
Different 3-D design of four half-banks. (a)Naive wide TSV Bus; (b) tightly
integrated TSV bus; (c)folded bank.
15. EXPERIMENTAL RESULTS
A heterogeneous 3-D DRAM chip with a 32-
entry SRAM row cache can improve
performance.
From our evaluation suggested that a
heterogeneous DRAM chip with a 32-entry
SRAM row cache can save dynamic energy of
a DRAM chip.
16. EXPERIMENTAL RESULTS
From this conservative study, our
heterogeneous 3-D DRAM chips with 8-, 16-,
and 32-entry SRAM row caches save energy.
Our evaluation with memory intensive
applications shows that well-balanced
heterogeneous 3-D DRAM chips can improve
system performance by 30% while saving
dynamic energy by 31%, on average.