Title :
A 90-MHz 16-Mb system integrated memory with direct interface to CPU
Author :
Dosaka, Katsumi ; Yamazaki, Akira ; Watanabe, Naoya ; Abe, Hideaki ; Ohtani, Tun ; Ogawa, Toshiyuki ; Ishihara, Kazunori ; Kumanoya, M.
Author_Institution :
ULSI Lab., Mitsubishi Electr. Corp., Itami, Japan
fDate :
4/1/1996 12:00:00 AM
Abstract :
This paper describes a system integrated memory with direct interface to CPU which integrates an SRAM, a DRAM, and control circuitry, including a tag memory (TAG). This memory realizes a computer system without glue chips, and thus enables a computer system which is low cost, low power, and compact size, but still with sufficient performance. Also fast clock cycle time and access time is realized using a newly proposed clock driver and internal signal generator. This memory is fabricated with a quad-polysilicon double-metal 0.55-μm CMOS process which is the same as used in a conventional 16-Mb DRAM. The chip size of 145.3 mm2 is only a 12% increase over the conventional 16-Mb DRAM. The maximum operating frequency is 90-MHz and the operating current at cache-bit is 156-mA. This memory is suitable for various types of computer systems such as personal digital assistants (PDA´s), personal computer systems, and embedded controller applications
Keywords :
CMOS memory circuits; DRAM chips; SRAM chips; timing; 0.55 micron; 156 mA; 16 Mbit; 90 MHz; DRAM; PDA application; SRAM; Si; clock driver; control circuitry; direct CPU interface; double-metal CMOS process; embedded controller applications; internal signal generator; personal computer systems; personal digital assistants; quad-polysilicon process; system integrated memory; tag memory; CMOS process; Clocks; Control systems; Costs; Driver circuits; Frequency; Personal digital assistants; Random access memory; Signal generators; Technical Activities Guide -TAG;
Journal_Title :
Solid-State Circuits, IEEE Journal of
