Cypress CY62167EV18 Manuel d'utilisateur télécharger pdf (Page 16)

US

2012/0147184

A1

camera

100

can

act

as

a

“slave”

unit

and

the

commands

for

the

processing

elements

described

below

can

be

issued

directly

from

the

base

station

160.

[0078]

In

general,

all

the

processing

can

operate

on

cycles

independent

of

each

other

to

maintain

maximum

ef?ciency.

Memory

can

be

used

to

buffer data

betWeen

processes

to

alloW

for

this.

This

buffering

memory

can

be

used

to

ensure

that

data

overrun

or

data

under-run

does

not

occur

during

operation.

This

buffering

memory

can

be

designed

to

operate

at

an

extremely

loW

poWer

during

non

active

or

retention

modes

that

can

occur

betWeen

processing

cycles.

This buff

ering

memory

can

be

distributed

betWeen

some

or

all

of

various

integrated

circuits

that

constitute

the

Wireless

camera

100.

Alternatively,

a

portion

of

the

buffering

can

be concen

trated

in

specialiZed

memory

components.An

example

of

this

kind

of

memory

component

can

be

the

Cypress

Semiconduc

tor

Corporation’s

16

Mbit

SRAM

memory

product

CY62167EV18.

[0079]

As

shoWn

in

FIG.

1,

a

number

of

modules

can

inter

face

to

the

CPU

110.

The

image

capturing

module

120 can

include

a

loW

poWer

imager

such

as

a

CMOS

based

sensor.

Alternatively,

a

CCD

can be

used,

but

typically

these

devices

use

more

energy

than

CMOS

devices

for

a

given

frame

rate,

resolution

and

?delity.

The

circuitry

supporting

the

sensor

can

include

memory

to

temporarily

hold

uncompressed

images.

In

one

implementation,

image

capturing

module

120

can

also

include

an

image

compression

engine

and

memory

that stores

both

compressed

and

uncompressed

images.

In

some

CMOS

imagers,

so

called

“active

pixel”

technology

can

be

used

to

alloW

the

imager

to

poWer

up

and

respond

very

rapidly

to

an

image

exposure

command

and

then

automati

cally

poWer

doWn.

[0080]

In

some

implementations,

the

imager

can

have

a

number

of

active

circuits

per

pixel

(such

as

analog

to

digital

converters)

to

enable

for

rapid

operation

for

brief

periods

of

time,

folloWed

by

very

loW

poWer

standby

energy

consump

tion.

This

also

means

that

the

instantaneous

poWer

consump

tion

of

the

imager

can be

relatively

large

during

the

frame

capture

and

transfer

process. In

an

alternative

energy

saving

implementation,

the

compression

circuitry

including

the

required

memory

can

be

integrated

directly

onto

the

image

capturing

module

120

or

even

directly

onto

the

image

sensor

die.

This

further

integration

can

reduce

the

energy

needed

to

transfer

data

and

control

information

betWeen

integrated

cir

cuits.

[0081]

The

sound

detection

module

122

can

generate

com

pressed

or

uncompressed

audio

data.

If

uncompressed

data

is

generated

from

module

122

then

the

CPU

110

can

perform

the

compression.

The

sound

detection

module

122

can

also

operate

at

loW

poWer,

e.g.,

in

the

order

of

tens

of

micro

Watts

and

provide

a

trigger

output

based

on

the

noise

level.

The

noise-level

triggering

event

can be

detection

of

a

shock

Wave,

detection

of

breaking

or

shattering glass

detection

or

other

similar

acoustic

detection

techniques.

In

some

implementa

tions,

the

sound

detection

module

122

can

operate

continu

ously

and

a

positive

noise

trigger

output

can be

used

to

acti

vate

the

Wireless

camera

100

from

a

standby

mode.

Once

activated,

the

Wireless

camera

100

can

initiate

the

various

processing

sections

to

start

cycling

and,

for

example,

start

sending

the

surveillance

data

to

the

base

station

160.

[0082]

In

another

noise-level

triggering

mode

the

sound

detection

module

122 and

the

image

capturing

module

120

can

continuously

capture

and

store

an

on-going

WindoW

of

surveillance

data

of

the

immediately

previous

seconds,

min

Jun.

14,

2012

utes

or

hours.

During

this

time

the

bulk

high-bandWidth

radio

104 can

be

inactive

in

order

to

save

poWer.

HoWever,

once

motion

is

detected

some

or

all

of

the

previously

stored

infor

mation can

be

transmitted

to

the

base

station

or

retrieved

in

other

Ways.

This

alloWs

the

activities

that

occurred

in

the

area

under

surveillance

prior

to

a

trigger

event

to

be

investigated.

[0083]

In

a

derivative

behavior

in

this

mode,

different

video

compression

algorithms

operating

at

different

rates

can

be

used

before

and

after

the

triggering

event.

For

example,

JPEG,

MJPEG

or

JPEG2000

type

compression

algorithms

can

be

used

during

the

pre-trigger

period

and

MPEG2

or

MPEG4

type

compression

algorithms

can

be

used

during

the

post

trigger

period.

This

can

avoid

losing

critical

captured

information

on

the

activities

in

the

surveillance

area

in

a

time

period

leading

up

to

the

triggering

event.

[0084]

The

infrared

detection

module

124

can

operate

at

loW

poWer,

in

the

order

of

tens

of

micro

Watts,

and

provide

a

trigger

output

that

indicates

motion

has

been

detected.

For

example,

the

infrared

detection

module

124

can be

imple

mented

With

a

pyroelectric infrared

sensor

With

a

Fresnel

lens.

In

some

implementations,

the

infrared

detection

module

124

can

operate

continuously

and

a

positive

noise

trigger

output

Will

activate

the

Wireless

camera

100

from

a

standby

mode.

Once

activated,

the

Wireless

camera

100

can

initiate

the

various

processing

sections

to

start

cycling

and,

for

example,

start

sending

the

surveillance

data

to

the

base

station

160.

[0085]

The

ultrasonic

detection

module

126

can

operate

at

loW

poWer,

in

the

order

of

tens

of

micro

Watts,

and

provide

a

trigger

output

that

indicates

motion

has

been

detected.

For

example,

the

ultrasonic

detection

module

126

can

be

imple

mented

With

a

ultrasonic

transmitter

that

sets

up

a

speci?c

sound

Wave

pattern

that

is

received

by

an

ultrasonic

receiver.

Motion

of

objects

in

the

?eld

of

the

sound

pattern

can

affect

the

received

ultrasonic

pattern

by

the

receiver.

These

changes

can

be

detected

by

the

ultrasonic

receiver

circuitry

in

the

ultrasonic

receiver

and

this

event

can

be

used

to

activate

the

Wireless

camera 100

from

a

standby

mode.

Once

activated,

the

Wireless

camera

100

can

initiate

the

various

processing

sections

to

start

cycling

and,

for

example,

start

sending

the

surveillance

data

to

the

base

station

160.

[0086]

In

another

noise-level

triggering

mode

the

infrared

detection

module

124

and/or

the

ultrasonic

detection

module

126

and

the

compression

and/or

capture

processing

engine

can

continuously

capture

and

store

an

on-going

WindoW

of

surveillance

data

of

the

immediately

previous

seconds,

min

utes

or

hours.

During

this

time

the

bulk

high-bandWidth

radio

104 can

be

inactive

in

order

to

save

poWer.

HoWever,

once

motion

is

detected

some

or

all

of

the

previously

stored

infor

mation can

be

transmitted

to

the

base

station

or

retrieved

in

other

Ways.

This

alloWs

the

activities

that

occurred

in

the

area

under

surveillance

prior

to

a

trigger

event

to

be

investigated.

In

addition,

other

detection

methods

can

be

implemented

in

a

manner

similar

to that

described

above

for

the

infrared

or

ultrasonic

detection,

but

the

triggering

events

can

be

initiated

by

other

sensors

including

magnetic

sensors,

relay

or

micro

sWitches

and

WindoW

screen

Wired

detectors.

[0087]

The

bulk

high-bandWidth

radio

104

can be

a radio

frequency

and

baseband

chip

set

that

implements

the

physical

layer

of

the

802.11

standard.

A

key

purpose

of

this

radio

transceiver

is

to

transfer

the

bulk

of

the

captured

and

com

pressed

surveillance

data

to

the

base

station

160.

The

MAC

and

other

circuitry

may

or

may

not

comply

With

802.11

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