dual ported

A term used to describe memory integrated circuits which can

be accessed simultaneously via two independent address and

data busses.

Dual ported memory is often used in video display hardware,

especially in conjunction with Video Random Access Memory

(VRAM). The two ports allow the video display hardware to

read memory to display the contents on screen at the same time

as the CPU writes data to other areas of the same memory. In

single-ported memory these two processes cannot occur

simultanteously, the CPU must wait, thus resulting in slower

access times. Cycle stealing is one technique used to avoid

this in single-ported video memory.

(1995-01-12)