Slide 1-1

Memory (an introduction)

Digital Techniques Fall 2007 André Deutz, Leiden University

D

CLK

Symbol

Q

Q

Circuit

D Q

C Q

Recall the clocked D(data) latch:

Slide 1-2Aside:Edge triggered/level triggered

Digital Techniques Fall 2007 André Deutz, Leiden University

C

BA D

A

Time

What is the voltage at D?

Slide 1-3

Edge triggered

Digital Techniques Fall 2007 André Deutz, Leiden University

D

Symbol

Q

Q

Circuit

C

BCl ock

D Q

C Q

Slide 1-4

Digital Techniques Fall 2007 André Deutz, Leiden University

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

mem

ory

Word 0

Word 1

Word 2

Word 3

I2I1I0

Data In

Writing to a memory word

Slide 1-5

Digital Techniques Fall 2007 André Deutz, Leiden University

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

mem

ory

Word 0

Word 1

Word 2

Word 3

I2I1I0

Data In

Writing to a memory word

Slide 1-6

Digital Techniques Fall 2007 André Deutz, Leiden University

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

mem

ory

Word 0

Word 1

Word 2

Word 3

I2I1I0

Data In

2 to

4 d

ecod

er

Writing to a memory word

a1

a0

Slide 1-7

Digital Techniques Fall 2007 André Deutz, Leiden University

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

mem

ory

Word 0

Word 1

Word 2

Word 3

I2I1I0

Data In

2 to

4 d

ecod

er

enable

a1

a0

Writing to a memory word

Slide 1-8

Digital Techniques Fall 2007 André Deutz, Leiden University

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

mem

ory

Word 0

Word 1

Word 2

Word 3

I2I1I0

Data In

enable

a1 a0

Writing to a memory word

Slide 1-9

Digital Techniques Fall 2007 André Deutz, Leiden University

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

mem

ory

Word 0

Word 1

Word 2

Word 3

I2I1I0

Data In

2 to

4 d

ecod

er

enable

a1

a0

Writing to a memory word

Slide 1-10

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

mem

ory

Word 0

Word 1

Word 2

Word 3

I2I1I0

Data In

2 to

4 d

ecod

er

a1

a0

Reading a mem word

Slide 1-11

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

mem

ory

Word 0

Word 1

Word 2

Word 3

I2I1I0

Data In

2 to

4 d

ecod

er

enable

a1

a0

Slide 1-12

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

mem

ory

Word 0

Word 1

Word 2

Word 3

I2I1I0

Data In

2 to

4 d

ecod

er

enable

a1

a0

Slide 1-13

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

D Q

CQ

mem

ory

Word 0

Word 1

Word 2

Word 3

I2I1I0

Data In

2 to

4 d

ecod

er

enable

a1

a0