مدار مجتمع (آی سی) آی سی‌کاربرد ویژه

Product Attributes

Introduction

The CY7C909 and CY7C911 are high-speed 4-bit-wide address sequencers for controlling the execution sequence of microinstructions in microprogrammed memory. They can be connected in parallel to expand the address width in 4-bit increments. Both devices utilize high-performance CMOS technology for optimum speed and power consumption. The CY7C909 can select an address from four sources: four external direct inputs, external data stored in an internal register, a 4-word-deep push/pull stack, or a program counter register. The push/pull stack includes control lines to facilitate efficient nested subroutine linkage. In the CY7C909, each of the four outputs can be OR'd with an external input to implement conditional skip or branch instructions. A zero input line forces all outputs to zero. Outputs are three-state, controlled by an output enable input. The CY7C911 is identical in circuit to the CY7C909, except that the four OR inputs are removed and the D and R inputs are tied together. The CY7C911 is available in a 20-pin, 300-mil package.

Features

• CY7C909/11 minimum clock-to-output cycle time of 30ns
• Maximum operating current 55mA
• Supply voltage tolerance -5V ±10%
• All parameters guaranteed over commercial operating temperature range
• Expandable in 4-bit increments without limit
• ESD withstand voltage greater than 2001V
• Pin-compatible and functionally equivalent to Am2909A/Am2911A

Applications

• Microprogram control
• Address sequencing
• Subroutine execution