ATT Test 8 2025 NEW

ATT Test 8 2025 NEW

This guide provides a structured overview of digital circuits, logic gates, flip-
flops, registers, timers, and memory, crucial for the ATT Test 8.

I. Digital Circuit Fundamentals

 Sequential Circuits:

o Use feedback lines.

 Word:

o A complete digital data piece.

 Flip-Flops:

o Store information via output-to-input feedback.

o level triggering uses low pulse width.

 Registers:

o Store and transfer data.

 Logic Probe:

o Red LED indicates a high signal.

 Integrated Circuits (ICs):

o Enabled by semiconductor invention.

o Common features: Pins, part number, pin indicator.

 IC Families:

o CMOS: Lowest power rating/requirements, 0V-15V input/output.

o ECL: Fastest switching speed.

o TTL: Lower power than ECL.

 Digital Signal Classification:

o Presence: 5V/high/true/on.

o Absence: 0V/low/false/off.

 Voltage Levels:

o Low: 0-0.8V.

, o High: 2V or more.

o float: 0.8-2v.

 IC Classification by Gate Count:

o SSI: <12 gates.

o MSI: 12-99 gates.

o LSI: 100-9,999 gates.

o VLSI: 10,000-99,999 gates.

o ULSI: 100,000+ gates.

 Buffer Functions:

o Protection, driver, switching.

 ESD Sensitivity:

o Low operating current and voltage levels.

 Basic Digital Circuit Function:

o presence or absence of a signal.

II. Logic Gates and Functions

 Decimal Encoder:

o Decimal to binary conversion.

 Binary Decoder:

o Binary to alphanumeric conversion.

 AND Gate:

o High output when all inputs are high.

 NAND Gate:

o Low output when all inputs are high.

 NOR Gate:

o High output when all inputs are low.

o Low output when any input is high.

 XOR Gate: