A high-performance CMOS 32-bit parallel CRC engine

Design highlights for a 32-bit parallel cyclic redundancy check (CRC) generator engine are presented. In a 0.8-μm three-layer-metal CMOS process, the engine could handle about 5 Gbps data throughput. A compact layout is achieved by predecoding eight groups of four bits followed by performing a binary tree reduction on nets that are sorted by fanout. There are six gate delays plus a single-phase clock edge-triggered register     

A low-power 22-bit incremental ADC

This paper describes a low-power 22-bit incremental ADC, including an on-chip digital filter and a low-noise/low-drift oscillator, realized in a 0.6-/spl mu/m CMOS process. It incorporates a novel offset-cancellation scheme based on fractal sequences, a novel high-accuracy gain control circuit, and a novel reduced-complexity realization for the on-chip sinc filter. The measured output noise was 0.25 ppm (2.5 /spl mu/V/sub RMS/), the DC offset 2 /spl mu/V, the gain error 2 ppm, and the INL 4 ppm. The chip operates with a single 2.7-5 V supply, and draws only 120 /spl mu/A current during conversion.     

A low-power high-performance current-mode multiport SRAM

This paper presents a new approach for energy reduction and speed improvement of multiport SRAMs. The key idea is to use current-mode for both read and write operations. To toggle a memory cell, a very small voltage swing is first created on the high-capacitive bit lines. This voltage is then translated into a differential current being injected into the cell, which in turn allows complementary potential to be developed on the cell nodes. As compared to the conventional write approach, SPICE simulations using a 0.35-μm CMOS process have shown 2.8 to 9.9× in energy savings and 1.02 to 6.36× reduction in delay, for memory sizes of 32 to 1 K words. We also present a current-mode sense-amplifier that operates in a similar fashion as the write circuit. The design and implementation of a pipelined 32×64 three-port register file utilizing the proposed technique is described. Measurements of the register file chip have confirmed the feasibility of the approach     

一种低功耗10位流水线结构的CMOS A/D转换器的设计

本文设计了一种可满足视频速度应用的低电压低功耗10位流水线结构的CMOS A/D转换器.该转换器由9个低功耗运算放大器和19个比较器组成,采用1.5位/级共9级流水线结构,级间增益为2并带有数字校正逻辑.为了提高其抗噪声能力及降低二阶谐波失真,该A/D转换器采用了全差分结构.全芯片模拟结果表明,在3V工作电压下,以20MHz的速度对2MHz的输入信号进行采样时,其信噪失调比达到53dB,功率消耗为28.7mW.最后,基于0.6μm CMOS工艺得到该A/D转换器核的芯片面积为1.55mm2.     

A GaAs low-power normally-on 4-bit ripple carry adder

The realization and performance of a low-power buffered FET logic (1p-BFL) 4 bit ripple carry adder is reported. Performance measurements indicate a critical path average propagation delay of 1.9 ns at a total power dissipation of 45 mW, output buffers included (27 mW without). This corresponds to an average propagation delay of 380 ps/gate (FI/FO=/SUP 5///SUB 3/), an average power consumption of 1.56 mW/gate, and a power-delay product of 0.6 pJ. Best speed performance biasing conditions yield a 1.25 ns critical path average propagation delay at a total power dissipation of 180 mW (180 mW excluding buffers), which corresponds to an average gate delay, power consumption and power-delay product of 250 ps, 6 mW, and 1.5 pJ, respectively. Standard cell layout techniques yield an average gate density of 200 gates/mm/SUP 2/, interconnection wiring included.     

A 32-bit microprocessor for Smalltalk

SOAR (Smalltalk on a RISC), a 32-bit microprocessor designed for the efficient execution of compiled Smalltalk, is described. The chip, implemented in 4-/spl mu/m single-level metal NMOS technologies, has a cycle time of 400 ns. Pipelining allows an instruction to start each cycle with the exception of loads and stores. The processor contains 35700 transistors, is 320/spl times/432 mil, dissipates 3 W, and is assembled in an 84-lead pin grid array package. A design methodology that included a large CAD effort and provided functioning chips on first silicon was used. The SOAR hardware environment is a SUN workstation that includes a custom SOAR board and extra memory.     

A 32-bit VLSI CPU chip

A fully integrated 32-bit VLSI CPU chip utilizing 1 /spl mu/m features is described. It is fabricated in an n-channel silicon gate, self-aligned technology. The chip contains about 450000 transistors and executes microinstructions at approximately one per 55 ns clock cycle. It can execute a 32-bit binary integer add in 55 ns, a 32-bit binary integer multiply in 1.8 /spl mu/s, and a 64-bit floating point multiply in 10.4 /spl mu/s. The instruction set provides the functions of an advanced mainframe CPU. Because the implementation of such a complex device poses an organizational as well as a technical challenge, the design philosophy that was adopted is summarized briefly. Careful attention was paid to designer productivity, and design flexibility and testability.     

A low-power transmission-gate-based 16-bit multiplier for digital hearing aids

The most widespread 16-bit multiplier architectures are compared in terms of area occupation, dissipated energy, and EDP (Energy-Delay Product) in view of low-power low-voltage signal processing for digital hearing aids and similar applications. Transistor-level simulations including back-annotated wire parasitics confirm that the propagation of glitches along uneven and re-convergent paths results in large unproductive node activity. Because of their shorter full-adder chains, Wallace-tree multipliers indeed dissipate less energy than the carry-save (CSM) and other traditional array multipliers (6.0 µW/MHz versus 10.9 µW/MHz and more for 0.25 µm CMOS technology at 0.75 V). By combining the Wallace-tree architecture with transmission gates (TGs), a new approach is proposed to improve the energy efficiency further (3.1 µW/MHz), beyond recently published low-power architectures. Besides the reduction of the overall capacitance, minimum-sized transmission gate full-adders act as RC-low-pass filters that attenuate undesired switching. Finally, minimum size TGs increase the V _dd to ground resistance, hence decreasing leakage dissipation (0.55 nW versus 0.84 nW in CSM and 0.94 nW in Wallace).     

A mixed-signal approach to high-performance low-power linearfilters

We present a new approach to the design of high-performance low-power linear filters. We use p-channel synapse transistors as analog memory cells, and mixed-signal circuits for fast low-power arithmetic. To demonstrate the effectiveness of our approach, we have built a 16-tap 7-b 200-MHz mixed-signal finite-impulse response (FIR) filter that consumes 3 mW at 3.3 V. The filter uses synapse pFETs to store the analog tap coefficients, electron tunneling and hot-electron injection to modify the coefficient values, digital registers for the delay line, and multiplying digital-to-analog converters to multiply the digital delay-line values with the analog tap coefficients. The measured maximum clock speed is 225 MHz; the measured tap-multiplier resolution is 7 b at 200 MHz. The total die area is 0.13 mm². We can readily scale our design to longer delay lines     

A low-power transponder IC for high-performance identificationsystems

A novel CMOS integrated circuit for a batteryless transponder system is presented. Batteryless transponders require contactless transmission of both the information and power between a mobile data carrier and a stationary or handheld reader unit. The operating principle of this system gives a superior performance in reading distance due to separation of the powering and data transmission phases-compared to systems with continuous powering and damping modulation. This paper describes the function of the transponder IC and the circuit design techniques used for the various building blocks     

A 32-bit VLSI digital signal processor

A general-purpose programmable digital signal processor (DSP) has been implemented in 1.5-/spl mu/m (L/SUB eff/) NMOS technology using full-custom circuit design for high performance. The DSP has a 32-bit instruction set, 32-bit data path, and full-hardware 32-bit floating-point arithmetic. The architecture is described section by section, and an overview of the instruction set is presented. The extensive design verification process applied to the DSP is also described.     

A 32-bit logarithmic number system processor

To design a 32-bit logarithmic number system (LNS) processor, this paper presents two novel techniques: Digit-Partition (DP) to design log₂(1.x) function and Iterative Difference by Linear Approximation (IDLA) to design 2^0.x function. The basic concept behind DP is that variablex can be divided into two parts in bit representation to be implemented. Thus, ROM or PLA table can be reduced to a reasonable size and this will make a high precision design allowable. The basic idea of IDLA is that the function 2^0.x can be obtained approximately through iterative linear approximations. By this method, only adder, shifter and a small PLA are required, unlike the previous designs which require ROM and multiplier. The experiment results reveal that the proposed design is more attractive than the previous researches in the LNS processor.This work was supported by the National Science Council under Grant NSC 84-2215-E002-020.     

32位可配置系统芯片Triscend A7系列

它是Triscend的第二代CSoC,包括Triscend CSoC平台、32位RISC处理器ARM7TDMI内核、CPU子系统以及丰富的系统级功能。 A7为网络及因特网无线应用产品的单芯片解决方案加速了进入市场的时间。     

A 19-bit low-power multibit sigma-delta ADC based on data weightedaveraging

This paper describes a low-power multibit sigma-delta analog-to-digital converter (ADC) which achieves 19-b resolution. Multibit quantization and feedback within a sigma-delta loop are shown to provide a power-efficient solution for high-resolution converters. As the linearity of the digital-to-analog converter (DAC) in the feedback path is a critical issue, a comparison of different DAC solutions is made demonstrating the efficiency of the data weighted averaging algorithm. An implementation of this technique within a monolithic sigma-delta ADC is then described. The whole chip, including the digital decimation filter, consumes only 2.7 mW for an 800-Hz output rate. The resolution and linearity improvement brought by data weighted averaging is confirmed by measurements     

A low-power 1 MHz, 25 mW 12-bit time-interleaved analog-to-digitalconverter

A 12-bit 1 Msample/s 25 mW analog-to-digital converter was designed. Linearity, offset, and gain errors of less than 1/2 LSB have been achieved using an EEPROM memory trimming scheme. The EEPROM memory array, programmed during testing, continuously drives a correction digital-to-analog converter (DAC) with code dependent correction factors. The analog-to-digital converter (ADC) uses a time-interleaved multistep architecture consisting of two banks of comparator arrays sharing a common reference ladder and EEPROM correction memory. A static EEPROM memory array optimizes the power dissipation, conversion rate, inter-stage gain errors, and charge injection. The resulting converter achieves high speed operation with minimal power dissipation     

A low-power and high-performance CMOS fingerprint sensing andencoding architecture

A CMOS fingerprint sensor architecture with embedded cellular logic for image processing is presented. The system senses a fingerprint image with a capacitive technique and performs several image-processing algorithms, including thinning the ridges of the fingerprint structure and encoding it to its characteristic features. Image processing is achieved by application of hexagonal local operators implemented in pixel-parallel mixed neuron-MOS/CMOS logic circuits. The massive parallelism of the architecture leads to a very low power dissipation. Results of simulations and measurements on a demonstrator chip in 0.65-μm double-poly standard CMOS technology are shown. The approach is well suited for person-identification applications, especially in small and low-cost portable systems, such as smart cards     

A high-performance low-power CMOS AGC for GPS application

In this paper, a wide tuning range, low power CMOS automatic gain control (AGC) with a simple architecture is proposed. The proposed AGC is composed of variable gain amplifier (VGA), comparator and charge pump, and the dB-linear gain is controlled by charge pump. The AGC was implemented in a 0.18um CMOS technology. The dynamic range of the VGA is more than 55dB, the bandwidth is 30MHz and the gain error lower than ±1.5dB over the full temperature and gain ranges. It is designed for GPS application and is fed from a single 1.8V power supply. The AGC power consumption is less than 5mW and area of the AGC is 700*450um2.     

A 32×32-bit multiplier using multiple-valued MOS current-modecircuits

A 32×32-bit multiplier using multiple-valued current-mode circuits has been fabricated in 2-μm CMOS technology. For the multiplier based on the radix-4 signed-digit number system, 32×32-bit two's complement multiplication can be performed with only three-stage signed-digit full adders using a binary-tree addition scheme. The chip contains about 23600 transistors and the effective multiplier size is about 3.2×5.2 mm², which is half that of the corresponding binary CMOS multiplier. The multiply time is less than 59 ns. The performance is considered comparable to that of the fastest binary multiplier reported     

近阈值低功耗8位微处理器的设计与实现

随着RFID、可穿戴设备和物联网等应用的兴起,低吞吐率、功耗和能耗敏感的芯片设计开始受到广泛的关注,基于阈值电压的低功耗电路设计成为新的发展方向。文中基于SMIC0.13μm1P6M混合信号工艺,通过设计面向近阈值电压的标准逻辑库,在采用标准Top-Down设计流程的基础上,完成了一款近阈值低功耗8位微处理器的设计。封装后芯片的测试结果表明,该微处理器的最低工作电压可达0.2V,工作频率1k Hz~25MHz。与基于传统逻辑库的微处理器比,在20MHz的工作频率下,功耗降低了36%。     

A high-performance low-power CMOS AGC for GPS application

A wide tuning range, low power CMOS automatic gain control (AGC) with a simple architecture is proposed. The proposed AGC is composed of a variable gain amplifier (VGA), a comparator and a charge pump, and the dB-linear gain is controlled by the charge pump. The AGC was implemented in a 0.18 μm CMOS technology. The dynamic range of the VGA is more than 55 dB, the bandwidth is 30 MHz, and the gain error is lower than ±1.5 dB over the full temperature and gain ranges. It is designed for GPS application and is fed from a single 1.8 V power supply.The AGC power consumption is less than 5 mW, and the area of the AGC is 700 × 450 μm~2.