Browsing by Author "Lien, Nan-Chun"

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A 40 nm 512 kb Cross-Point 8 T Pipeline SRAM With Binary Word-Line Boosting Control, Ripple Bit-Line and Adaptive Data-Aware Write-Assist
(2014-12-01)
Lien, Nan-Chun
;
Chu, Li-Wei
;
Chen, Chien-Hen
;
Yang, Hao-I.
;
Tu, Ming-Hsien
This paper presents a cross-point 512 kb 8 T pipeline static random-access memory (SRAM). The cross-point structure eliminates write half-select disturb to facilitate bit-interleaving architecture for enhanced soft error immunity. The design employs boosted word-line (WL) for improving both read performance and write-ability. A ripple bit-line (RiBL) structure provides 30%-44% read access performance improvement and 2x-3.5x variation immunity at 0.7 V compared with the conventional hierarchical bit-line (HiBL) schemes. An adaptive data-aware write-assist (ADAWA) with VCS tracking is employed to further enhance the write-ability while ensuring adequate stability for half-selected cells on the selected bit-lines. An adaptive voltage detector (AVD) with binary boosting control is used to mitigating gate electric over-stress. The design is implemented in UMC 40 nm low-power (40LP) CMOS technology. The 512 kb test chip operates from 1.5 V to 0.65 V, with maximum operation frequency of 800 MHz@1.1 V and 200 MHz@0.65 V. The measured power consumption is 0.5 mW/MHz (active) and 4.4 mW (standby) at 1.1 V, and 0.107 mW/MHz (active) and 0.367 mW (standby) at 0.65 V.
A 40nm 1.0Mb 6T Pipeline SRAM with Digital-Based Bit-Line Under-Drive, Three-Step-Up Word-Line, Adaptive Data-Aware Write-Assist with VCS Tracking and Adaptive Voltage Detector for Boosting Control
(2013-01-01)
Liao, Wei-Nan
;
Lien, Nan-Chun
;
Chang, Chi-Shin
;
Chu, Li-Wei
;
Yang, Hao-I
This paper presents a 40nm 1.0Mb pipeline 6T SRAM featuring digital-based Bit-Line Under-Drive (BLUD) with large-signal sensing and Three-Step-Up Word-Line (TSUWL) to improve RSNM, Read performance and Write-ability. An Adaptive DataAware Write-Assist (ADAWA) with VCS tracking is employed to further improve Write-ability while ensuring adequate stability for half-selected cells on the selected bit-lines. An Adaptive Voltage Detector (AVD) with binary boosting control is used to mitigate gate dielectric over-stress. The 1.0Mb test chip operates from 1.5V to 0.7V, with operating frequency of 1.07GHz@1.2V and 887MHz@1.1V at 25 degrees C. The measured power consumption is 43.47mW (Active)/3.91mW (Leakage) at 1.1V and 8.97mW (Active)/0.52mW (Leakage) at 0.7V, TT, 25 degrees C.
A 40nm 1.0Mb Pipeline 6T SRAM with Variation-Tolerant Step-Up Word-Line and Adaptive Data-Aware Write-Assist
(2013)
Chang, Chi-Shin
;
Yang, Hao-I
;
Liao, Wei-Nan
;
Lin, Yi-Wei
;
Lien, Nan-Chun
We present a 1.0Mb pipeline 6T SRAM in 40nm Low-Power CMOS technology. The design employs a variation-tolerant Step-Up Word-Line (SUWL) to improve the Read Static Noise Margin (RSNM) without compromising the Read performance and Write-ability. The Write-ability is further enhanced by an Adaptive Data-Aware Write-Assist (ADAWA) scheme. The 1.0Mb test chip operates from 1.5V to 0.7V, with operating frequency of 800MHz@1.2V and 25 degrees C. The measured power consumption is 23.21mW (Active)/2.42mW (Leakage) at 1.2V, TT, 25 degrees C; and 6.01mW (Active)/0.35mW (Leakage) at 0.7V, TT, 25 degrees C.
A High-Performance Low V(MIN) 55nm 512Kb Disturb-Free 8T SRAM with Adaptive VVSS Control
(2011)
Yang, Hao-I
;
Yang, Shih-Chi
;
Hsia, Mao-Chih
;
Lin, Yung-Wei
;
Lin, Yi-Wei
This paper describes a high-performance low V(MIN) SRAM with a disturb-free 8T cell. The SRAM utilizes single-ended buffer Read, and cross-point data-aware Write Word-Line structure with adaptive VVSS control to eliminate Read disturb and Half-Select disturb, thus facilitating bit-interleaving architecture and achieving low V(MIN). A 512Kb test chip is implemented in UMC 55nm Standard Performance (SP) CMOS technology. The measurement results demonstrate operating frequency of 943MHz at 1.2V VDD and 209MHz at 0.6V VDD.
An All-Digital Bit Transistor Characterization Scheme for CMOS 6T SRAM Array
(2012)
Lin, Geng-Cing
;
Wang, Shao-Cheng
;
Lin, Yi-Wei
;
Tsai, Ming-Chien
;
Chuang, Ching-Te
We present an all-digital bit transistor characterization scheme for CMOS 6T SRAM array. The scheme employs an on-chip operational amplifier feedback loop to measure the individual threshold voltage (VTH) of 6T SRAM bit cell transistors (holding PMOS, pull-down NMOS, and access NMOS) in SRAM cell array environment. The measured voltage is converted to frequency with dual VCO and counter based digital read-out to facilitate data extraction, processing, and statistical analysis. A 512Kb test chip is implemented in 55nm 1P10M Standard Performance (SP) CMOS technology. Monte Carlo simulations indicate that the accuracy of the VTH measurement scheme is about 2-7mV at TT corner across temperature range from 85 degrees C to -45 degrees C, and post-layout simulations show the resolution of the digital read-out scheme is < 0.2mV per bit. Measured VTH distributions agree well with Monte Carlo simulation results.
Design and Implementation of Dynamic Word-Line Pulse Write Margin Monitor for SRAM
(2012)
Wang, Shao-Cheng
;
Lin, Geng-Cing
;
Lin, Yi-Wei
;
Tsai, Ming-Chien
;
Chiu, Yi-Wei
We present an all-digital monitor structure to measure the Write Margin (WM) with dynamic Word-Line (WL) pulse for standard CMOS 6T SRAM. Ring oscillator and frequency divider based structures are used to generate wide range WL pulses (150ps similar to 32ns) with resolution of 50ps. The bit-line voltage is then successively stepped down for dynamic Write Margin characterization under given word-line pulse width. An improved Skitter based structure is employed to measure the WL pulse width with resolution of 10 similar to 20ps. Implementation of a 256Kb test chip in UMC 55nm Standard Performance (SP) CMOS technology is described.
High-Performance 0.6V V-MIN 55nm 1.0Mb 6T SRAM with Adaptive BL Bleeder
(2012)
Yang, Hao-I
;
Lin, Yi-Wei
;
Hsia, Mao-Chih
;
Lin, Geng-Cing
;
Chang, Chi-Shin
This paper presents a 1.0Mb high-performance 0.6V V-MIN 6T SRAM design implemented in UMC 55nm Standard Performance (SP) CMOS technology. This design utilizes an adaptive LBL bleeder technique to reduce Read disturb and Half-Select disturb of 6T cells while maintaining adequate sensing margin. A bleeder timing control circuit adaptively adjusts the LBL voltage level prior to Read/Write operation to facilitate wide operation voltage range. Hierarchical WL, hierarchical BL, and distributed replica timing control scheme are used to improve SRAM performance. Based on measurement results, the SRAM operates from 1.5V down to 0.6V. The maximum operating frequency is 1.517GHz@1.5V and 469MHz@0.7V.
Method for Resolving Simultaneous Same-Row Access In Dual-Port 8T SRAM with Asynchronous Dual-Clock Operation
(2013-01-01)
Lien, Nan-Chun
;
Chuang, Ching-Te
;
Wu, Wen-Rang
;
電機資訊學士班
;
電子工程學系及電子研究所
This work proposes a novel Dual-Port (DP) 8T SRAM operation scheme. The scheme improves the Read stability and Write-ability, and allows asynchronous operation with arbitrary clock timing skew between two ports. It facilitates high performance, low-power and low VM1N with minimum device and area overhead. Postsimulation results show almost no timing penalty for simultaneous same-row access and the performance is almost the same as that for one port operation.