A 90-MHZ 16-MB SYSTEM INTEGRATED MEMORY WITH DIRECT INTERFACE TO CPU

This paper describes a system integrated memory with direct interface to CPU which integrates an SRAM, a DRAM, and control circuitry, includ ing 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, And f ast clock cycle time and access time is realized using a newly propose d clock driver and internal signal generator, This memory is fabricate d with a quad-polysilicon double-metal 0.55-mu m CMOS process which is the same as used in a conventional 16-Mb DRAM, The chip size of 145.3 mm(2) is only a 12% increase over the conventional 16-Mb DRAM. The ma ximum operating frequency is 90-MHz and the operating current at cache -hit 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.