6

ATF1508AS(L)

0784P–PLD–7/05

Figure 1. ATF1508AS Macrocell

Programmable

Pin-keeper

Option for

Inputs and I/Os

The ATF1508AS offers the option of programming all input and I/O pins so that “pin-keeper”

circuits can be utilized. When any pin is driven high or low and then subsequently left floating,

it will stay at that previous high- or low-level. This circuitry prevents unused input and I/O lines

from floating to intermediate voltage levels, which causes unnecessary power consumption

and system noise. The keeper circuits eliminate the need for external pull-up resistors and

eliminate their DC power consumption.

Input Diagram