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 single chip radix-2 FFT butterfly architecture using parallel data distributed arithmetic

It is shown how distributed arithmetic techniques can be applied in parallel-data arithmetic computations to achieve highly regular and efficient VLSI structures on silicon. Two individual arithmetic processor chips are described as examples of the technique. The chips described, which are intended primarily for computation of the FFT butterfly, each contain the functional equivalence of two parallel pipelined multipliers. The first chip is an 8-bit prototype device which has been designed and fabricated on a standard 5-/spl mu/m silicon-gate n-channel MOS process. The second chip is a 16-bit CMOS-SOS design which uses a modified architecture to achieve higher clocking rates and improved versatility in systems use.     

A self-testing 2-/spl mu/m CMOS chip set for FFT applications

A chip set for high-speed radix-2 fast Fourier transform (FFT) applications up to 512 points is described. The chip set comprises a (16+16)/spl times/(12+12)-bit complex number multiplier, and a 16-bit butterfly chip for data reordering, twiddle factor generation, and butterfly arithmetic. The chips have been implemented using a standard cell design methodology on a 2-/spl mu/m bulk CMOS process. Three chips implement a complex FFT butterfly with a throughput of 10 MHz, and are cascadable up to 512 points. The chips feature an offline self-testing capability.     

A 24-bit microprocessor for data communication systems designed on the basis of a general cell library

A 24-bit microprogrammed processor with 200 ns instruction cycle time has been realized as an experimental special purpose VLSI chip. The design was based on a general cell library and a set of advanced CAD tools. The technology used is a 3 /spl mu/m silicon gate, n-channel, single metallization MYMOS process. The chip integrates 9400 gate functions plus a 256/spl times/27 bit static RAM on 78.5 mm/SUP 2/.     

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 high-speed multiplier using a redundant binary adder tree

A 16-bit /spl times/ 16-bit multiplier for 2 two's-complement binary numbers based on a new algorithm is described. This multiplier has been fabricated on an LSI chip using a standard n-E/D MOS process technology with a 2.7-/spl mu/m design rule. This multiplier is characterized by use of a binary tree of redundant binary adders. In the new algorithm, n-bit multiplication is performed in a time proportional to log/SUB 2/ n and the physical design of the multiplier is constructed of a regular cellular array. This new algorithm has been proposed by N. Takagi et al. (1982, 1983). The 16-bit/spl times/16-bit multiplier chip size is 5.8 /spl times/ 6.3 mm/SUP 2/ using the new layout for a binary adder tree. The chip contains about 10600 transistors, and the longest logic path includes 46 gates. The multiplication time was measured as 120 ns. It is estimated that a 32-bit /spl times/ 32-bit multiplication time is about 140 ns.     

A 16-kbit nonvolatile charge addressed memory

A 16-kbit nonvolatile charge addressed memory (NOVCAM) is described. A unique cell design allows a high-density memory array layout without reduced line widths or spacings. A cell size of 0.5 square mils is produced by a seven mask process with 6-/spl mu/m polysilicon gates, 10-/spl mu/m aluminum gates, and 10-/spl mu/m minimum spacing on all mask levels. Charge addressed write and read operations are implemented with a very simple interface between the memory array and a two-phase dynamic shift register. The memory is organized as 256 columns by 64 rows. Two 64-bit shift registers provide data access to the memory array via a 2:1 column decoder. With single polysilicon processing the memory array is 50/spl times/161 mils; the 16-kbit chip is 131/spl times/200 mils.     

A configurable ROM circuit for use in gate arrays

A double word-line memory ROM (DWM-ROM) for use in gate arrays is described. It allows for an automatic layout by reducing the input pin count in the word lines by using two-step addressing. The advantage of this method has been verified by implementing a 16-bit microprocessor using an 8 K-gate array, based on a gate-isolated cell configuration, employing 1.5-/spl mu/m double-metal CMOS technology. The 16-bit /spl times/ 64-word ROM in the processor saves 30% of the transistor area due to the DWM-ROM.     

25-ns 256K/spl times/1/64K/spl times/4 CMOS SRAM's

Through a metal option, a 256K word/spl times/1-bit and a 64K word/spl times/4-bit CMOS SRAM organization has been obtained. A fast access time has been achieved with a short bit-line structure and a data-bus precharging technique which minimize the bit-line and data-bus delay. A feedback-controlled address-transition-detector circuit has been adopted to assure the fast access time in the presence of address skew. A 1.0-/spl mu/m double-polysilicon and single-metal process technology with a polycide gate offers a memory cell size of 90 /spl mu/m/SUP Z/ and a chip size of 47.4 mm/SUP 2/.     

A shared-well dual-supply-voltage 64-bit ALU

A shared n-well layout technique is developed for the design of dual-supply-voltage logic blocks. It is demonstrated on a design of a 64-bit arithmetic logic unit (ALU) module in domino logic. The second supply voltage is used to lower the power of noncritical paths in the sparse, radix-4 64-bit carry-lookahead adder and in the loopback bus. A 3 mm/sup 2/ test chip in 0.18-/spl mu/m 1.8-V five-metal with local interconnect CMOS technology that contains six ALUs and test circuitry operates at 1.16 GHz at the nominal supply. For target delay increase of 2.8% energy savings are 25.3% using dual supplies, while for 8.3% increase in delay, 33.3% can be saved.     

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 2-/spl mu/m CMOS 8-MIPS digital processor with parallel processing capability

A 2-/spl mu/m CMOS VLSI digital signal processor (DSP) family, the SP50, is described that is capable of eight million instructions per second and up to six concurrent operations in each instruction. Two DSPs, the PCB5010 and PCB5011, have been developed. Both are based on a common architecture which contains two 16-bit data buses, and a 16/spl times/16/spl rarr/40-bit multiplier accumulator and 16-bit ALU, both with multiprecision support in hardware. Also implemented are two static data RAMs (128/spl times/16 or 256/spl times/16), a data ROM (51/spl times/16), a 15-word three-port register file, three address computation units, and five serial and parallel I/O interfaces. The data path is controlled by an orthogonal instruction set, using 40-bit microcode words. The controller contains a five-level stack and an instruction repeat register, and can have either on-chip program memory (RAM: 32/spl times/40; ROM: 987/spl times/40) or off-chip program memory (up to 64K/spl times/40). Benchmarks show a two to sixfold improvement in overall performance over its predecessors.     

A 32-bit execution unit in an advanced NMOS technology

The circuit and design of an experimental 32-bit execution unit are described. It is fabricated in a scaled NMOS single-layer poly-technology with 2-/spl mu/m minimum gate length and low-ohmic polycide for gates and interconnections. The chip (25000 transistors, 16 mm/SUP 2/, 61 pins) is designed with a high degree of regularity and modularity. The circuit performs logic and arithmetic operations and has an on-chip control ROM for instruction decoding. It operates with a single 5-V supply voltage. Measurements resulted in a typical power dissipation of 750 mW and a maximum operation frequency of 6.5 MHz. At this frequency a 32/spl times/32 bit multiplication is performed in less than 5.5 /spl mu/s.     

A single-chip programmable platform based on a multithreaded processor and configurable logic clusters

This paper presents a single-chip programmable platform that integrates most of hardware blocks required in the design of embedded system chips. The platform includes a 32-bit multithreaded RISC processor (MT-RISC), configurable logic clusters (CLCs), programmable first-in-first-out (FIFO) memories, control circuitry, and on-chip memories. For rapid thread switch, a multithreaded processor equipped with a hardware thread scheduling unit is adopted, and configurable logics are grouped into clusters for IP-based design. By integrating both the multithreaded processor and the configurable logic on a single chip, high-level language-based designs can be easily accommodated by performing the complex and concurrent functions of a target chip on the multithreaded processor and implementing the external interface functions into the configurable logic clusters. A 64-mm/sup 2/ prototype chip integrating a four-threaded MT-RISC, three CLCs, programmable FIFOs, and 8-kB on-chip memories is fabricated in a 0.35-/spl mu/m CMOS technology with four metal layers, which operates at 100-MHz clock frequency and consumes 370 mW at 3.3-V power supply.     

A pipelined 50-MHz CMOS 64-bit floating-point arithmetic processor

A 135K transistor, uniformly pipelined 50-MHz CMOS 64-bit floating-point arithmetic processor chip is described. The execution unit is capable of sustaining pipelined performance of one 32-bit or 64-bit result every 20 ns for all operations except double-precision multiply (40 ns) and divide. The chip employs an exponent difference prediction scheme and a unified leading-one and sticky-bit computation logic for the addition and subtraction operations. A hardware multiplier using a radix-8 modified Booth algorithm and a divider using a radix-2 SRT algorithm are employed.<>     

CMOS image sensor with mixed-signal processor array

We present a single-chip integration of a CMOS image sensor with an embedded flexible processing array and dedicated analog-to-digital converter. The processor array is designed to perform convolution and transformation algorithms with arbitrary kernels. It has been designed to carry out the multiplication of analog image data with given digital kernel coefficients and to add up the results. The processor array is an analog implementation of a highly parallel architecture which is scalable to any desired sensor resolution while preserving video-rate operation. A prototype implementation has been realized in a 0.6-/spl mu/m CMOS technology. Switched current technique has been applied to obtain compact and robust circuits. The prototype's sensor resolution is 64 /spl times/ 128 pixels. The processor array occupies a small chip area and consumes only a small percentage of the power (250 /spl mu/W) of the whole image sensor.     

An experimental 4-Mbit CMOS DRAM

A 4-Mb dynamic RAM has been designed and fabricated using 1.0-/spl mu/m twin-tub CMOS technology. The memory array consists of trenched n-channel depletion-type capacitor cells in a p-well. Very high /spl alpha/-particle immunity was achieved with this structure. One cell measures 3.0/spl times/5.8 /spl mu/m/SUP 2/ yielding a chip size of 7.84/spl times/17.48 mm/SUP 2/. An on-chip voltage converter circuit was implemented as a mask option to investigate a possible solution to the MOSFET reliability problem caused by hot carriers. An 8-bit parallel test mode was introduced to reduce the RAM test time. Metal mask options provide static-column-mode and fast-age-mode operation. The chip is usable as /spl times/1 or /spl times/4 organizations with a bonding option. Using an external 5-V power supply, the row-address-strobe access time is 80 ns at room temperature. The typical active current is 60 mA at a 220-ns cycle time with a standby current of 0.5 mA.     

Micro/370: a 32-bit single-chip microprocessor

A 32-bit single-chip microprocessor is described that directly implements 102 System/370 instructions and supports the emulation of the rest of the instructions. It is fabricated using a 2-/spl mu/m polysilicon-gate NMOS technology with two levels of aluminium. The chip is 10/spl times/10 mm/SUP 2/ with 200000 transistor sites. It is designed for a 10-MHz clock at worst case and has been operated at 18 MHz with a 3-W power dissipation. The design and verification methodologies and the testing consideration are also described.     

A CMOS triple 100-Mbit/s video D/A converter with shift register and color map

A 100-Mb/s CMOS video digital-to-analog converter (VDAC) chip is described. The VDAC provides all output functions for a four-plane color video subsystem. Included in this chip are: direct drivers for 75-/spl Omega/ cables; three 100-MHz 4-bit DACs; a color-map memory; video shift registers; cursor logic and a processor interference. The design approaches for both the analog and digital circuitry are discussed. The bench and automatic testing of this high-speed, high-pin-count, combined analog/digital chip are presented.     

A 5-bit building block for 20 MHz A/D converters

Describes a monolithic, fully parallel 5-bit A/D converter. The chip is fabricated using a standard metal-gate enhancement depletion NMOS technology with 7 /spl mu/m minimum features. The chip contains 31 strobed comparators, latches, combinational logic, a 5/spl times/31 bit ROM, TTL buffers and a 4-bit DAC. This makes it a building block for two-step parallel 8-bit A/D converters. Maximum conversion rate is 20 MHz and DC linearity is better than /SUP 1///SUB 4/ LSB for 80 mV quantization step size.