DESCRIPTION
The M66221 is a mail box that incorporates a complete CMOS shared memory cell of 256 × 9-bit configuration using high-performance silicon gate CMOS process technology, and is equipped with two access ports of A and B.

FEATURES
• Memory configuration of 256 × 9 bits
• High-speed access, address access time 40ns (typ.)
• Complete asynchronous accessibility from ports A and B
• Completely static operation
• Built-in port arbitration function
• Low power dissipation CMOS design
• 5V single power supply
• Not Ready output pin is provided (open drain output)
• TTL direct-coupled I/O
• 3-state output for I/O pins.

APPLICATION
    Inter-MPU data transfer memory, buffer memory for image processing system.