BASIC BOOLEAN

OPERATIONS

AND, conjunction, Boolean product

X A B AB A B A B

OR, disjunction, Boolean sum

X A B A B A B

/ 'X A A A

NOT, negation, complement

The basics of digital circuits

we need a better switch…

Logic gate – an electronic device that implements the Boolean operation (function)

7400 (74LS00, 74HCT00)

The basics of digital circuits

X

X

A B

A B

X AB AB

The basics of digital circuits

• conductors

• semiconductors

• insulators (dielectrics) Silicon Lattice

5.4Å

unit cell

(face-centered diamond cubic cell)

The basics of digital circuits

Metal Oxide Semiconductor Field Effect Transistor – MOSFET

The basics of digital circuits

inversion layer!

VGS low

VGS high

Metal Oxide Semiconductor Field Effect Transistor – MOSFET

approx. dimensions:

4.6x3.6mm

The basics of digital circuits

CMOS – Complementary Metal Oxide Semiconductor

taken from: www.physics.udel.edu/~watson/scen103/mos4.html

The basics of digital circuits

n-channel MOSFETp-channel MOSFET

Source Gate Drain

n-type substrate

Vin

Vout

Logical

HI ‘1’

Logical

LOW ‘0’

Logical

LOW ‘0’

Logical

HI ‘1’

AND gate

The basics of digital circuits

NOT (inverter)

Simplified,

taken from:

P. Horowitz

Art of Electronics

CMOS

f[Hz]

power

dissipation

[mW]

+ very low (near zero…) static (or at low frequencies) power dissipation

+ high noise margin

+ nearly ideal voltage transfer characteristics, comparable rising and falling times

+ high fan-out (number of gated connected to one output)

+ today: relatively cheap, robust and

- problems with power dissipation (e.g. heat) at (very) high frequencies (>GHz)

2P CU f

supply voltage

switching

frequency

load

capacitance

CMOS technology

pros & cons

The power wall…

The chip manufacturing process

Intel

a 45nm logic

technology

Intel

a 22nm logic technology (np. Ivy Bridge)

http://newsroom.intel.com/docs/DOC-2032

The further improvement of computational efficiency…

• further increase of clock frequency –>

increased power consumption & heat dissipation

• further reduction of supply voltage –> lower noise immunity, lower switching times,

voltage drops… etc…

Some technical problems can be solved using modern, dense manufacturing

processes…

• current trends:

• multicore processors & multiprocessor computers

• instruction-level parallelism

• coprocessors, (GP)GPU , Intel Xeon PHI…

Silicon die of the modern CPU (Intel i5-i7)

• total power dissipation 90- 130W

• a few (or over a dozen) BIG and UNIVERSAL cores…

Intel Kaby Lake (14nm, 2016)

Technology progress:

14nm -> 10nm -> 7-5nm (2019)

Intel, Samsung, TSMC (Taiwan Semiconductor Manufacturing Company)

Si lattice constant: ok. 5.4Å (0.54nm) !

source: Intel

Another approach…

several dozens (hundreds) of SIMPLE cores

e.g Intel Atom cores - Intel Kinghts Langing (Xeon Phi), built-in 16GB RAM

Intel i7

SUN UltraSPARC T3

IBM

Power

A2

IBM

Cell

Methods of designing digital circuits

• classical approach:

• determine all the necessary input signals and behaviour of outputs

• create the truth (or Karnough) tables for each output signal

• perform minimization and write final Boolean expressions

• draw appropriate schematic diagram

• Hardware Description Language (HDL) + Programmable Logic Device (CPLD/FPGA)

(Complex Programmable Logic Device / Field-Programmable Gate Array)

• CUPL

• VHDL

• Verilog

ULA –

Uncommitted Logic

Array

Verilog

Reversible

Counter

mod 16

Logical structure

of PLD

/romwr = /WR + A13 + A14 + A15 + rom + /cm

CUPL – boolean equation:

Hardware Description

Languages:

FPGA structure & logic cells

FPGA

Field-Programmable Gate Array

opencores.org

Microcontroller 1986VE91T (ARM Cortex M3), proces 180nm

(manufacturer Milandr, Russia)

made of synthesized cells and blocks…

zeptobars.com/en/read/MDR32F9Q2I-1986VE91T-whats-inside-russian-arm