Ikuro Masuda

CMOS/bipolar circuits for 60-MHz digital processing

High-performance bipolar/CMOS (Hi-BiCMOS) technology, in which a bipolar transistor of 4-GHz cutoff frequency is combined with standard CMOS devices on the same chip, has been applied to a processor. The design strategy was to provide high integration density using the CMOS circuit and accelerate the critical paths using the Hi-BiCMOS circuits. Hi-BiCMOS circuits with low-voltage swing have been developed and applied to a 32-bit arithmetic logic unit and a 128-kb ROM with bipolar drivers to drive a heavy load capacitance. A 17-ns 32-bit carry propagation delay time and a 17-ns ROM access cycle time have been achieved using 2-/spl mu/m Hi-BiCMOS technology. A minicomputer CPU with a 60-MHz machine cycle can be implemented with these circuits.

13-ns, 500-mW, 64-kbit ECL RAM using Hi-BiCMOS technology

The development is discussed for a 13-ns, 500-mW, 16K word/spl times/4-bit emitter-coupled logic (ECL) RAM using high-performance bipolar CMOS (Hi-BiCMOS) technology that combines a bipolar and a CMOS device on the same chip. The power dissipation of the RAM is about one half that of the conventional 64-kb bipolar ECL RAM. This high-speed, low-power RAM has been realized through a concept of a MOS-type memory cell, bipolar circuits, and a CMOS combination gate to allow for increased LSI integration.

A 13ns/500mW 64Kb ECL RAM

This paper will cover the design of a 16K×4 SRAM which uses buried twin-well 2μm CMOS transistors and 4GHz cutoff frequency bipolar transistors. The circuit combines a high-resistance polysilicon - load NMOS memory cell with mixed MOS/bipolar periphery circuits to achieve ECL compatibility, 13ns access times and an operating power of 500mW at 40MHz.

A 4K CMOS gate array with automatically generated test circuits

A 2-/spl mu/m CMOS 4K-gate array using a newly devised scan bus method has been developed. This method is applied to the array by using a double-latch structure, parallel scanning, and normal-test common pin techniques. The gate array can be tested for 95-100% of all DC faults using computer-generated test circuits and test data, without placing restrictions on the logic design. Due to an access-to-output flip-flop structure and a gate-isolated three-input type basic cell, including embedded transistors, the area increase and operating speed degradation due to test circuits are considerably reduced. Furthermore, besides the flip-flop blocks, a built-in RAM macroblock is available. Degradation of operating speed is evaluated as 10%. The scan operation is done at a clock cycle of 120 ns, and the access time of the RAM macroblock is 34 ns. The gate array includes 4032 three-input gates on a 7.2/spl times/7.02-mm chip.

A fault tolerant MOS-LSI for train controller applications

Fault-tolerant design techniques, which have resulted in the development of a fail-safe LSI circuit for train control applications, will be discussed. The design is based on bit-serial, time-sharing and frequency domain operation, as well as a layout method to restrict possible MOS failure modes.

Development of a Custom LSI for Industrial Data Communication

A new custom LSI for industrial data communication systems has been developed. This LSI provides all of the functions required for data communication between control equipment and plants without any additional circuits or software. It is also versatile enough to be adaptable to many kinds of industrial control systems.