digital lecture

8/15/2019 Digital Lecture

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ReviewECE 3710

reading:

1. V1.Ch1.1--6, V2.Ch1.52.V1.Ch1.7-9,Ch2.1-2


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No one knows what’s next,

but everybody does it.- George Carlin


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for what follows...

Most Likely You Go Your Way (And I'll Go Mine)- Bob Dylan


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binary

2^8 = 256 => 256 representations

8 bits: 0000 0000 {

byte


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bin2dec

1111 1111

2^7+2^6+2^5+2^4+2^3+2^2+2^1+2^0 = 255

0

7


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bin2dec

Q: 0101 0101

A. 170B. 86

C. 85D. 43


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bin2dec

A: 2^6+2^4+2^2+2^0 = 85

Q: 0101 0101


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never, ever use this:

"There are 10 types of people: those

who understand binary and everyoneelse."


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if you think it’s funny...


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dec2bin

275 => 1 0001 0011

bits:1. how many

2. which


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dec2bin

275 > 255 => more than 8275 < 511 => no more than 9

275 => 1 0001 0011


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dec2bin

{

19 = 1 0001 XXXX (need bit in 4th position)

275 => 1 0001 0011

2^8 + 2^(i-1) + …


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hex

hex2dec & dec2hex

use bin as intermediary(4-bits represent 16 combinations)

denoting hex numbers:

AAH0xAA


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Q: dec2bin(34) & dec2hex(34)


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Q: dec2bin(34) & dec2hex(34)

2^5 = 32 and 2^6=64 => 6 bits: 0010 0000

32 + 2 = 34 => 0010 0010

22H


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Q: hex2dec(0xA5)

A. 163B. 164C. 165D. 166


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Q: hex2dec(A5)

10 5

1010 0101

2^7+2^5+2^2+2^0=128+32+4+1=165

shouldn’t need table:

(memorise all 4-bit)


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Q: 0x36B+0xF6


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Q:36BH+F6H

11

36B+ F6

=0x461

1: 11+6=17 (-16=1)2:6+15+1=22 (-16=6)3: 3+1=4


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Q: 36BH-F6H

A. 0x275

B. 0x286

C. 0x297

D. 0x2A8


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Q: 0x36B-0xF6

36B

- F6

=0x275

1: 11-6=52:6-15+16=73: 2


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decoder


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multiplexor


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flip-flop (d latch)

previous clock: Q = 1

want: = 0

1

0 1

Q0 = 0

0

1

0

1

10

1

1

0

1

00

1

0

1

1

0


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who makes a 112GB HDD?

I bought a 120GB HDD


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http://www.tarsnap.com/GB-why.html

http://www.tarsnap.com/GB-why.html


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Bit : a binary digit that can have the value0 or 1

Byte : 8 bits

Nibble : half of a bye, or 4 bits

Word : two bytes, or 16 bits

arch. dependent;ARM = 32 bits

terminology for memory only

IEC

Kibibyte (KiB)Mebibyte (MiB)Gibibyte (GiB)Tebibyte (TiB)

Kilobyte (K): 210 bytes

Megabyte (M) : 220 bytes, over 1 million

Gigabyte (G) : 230 bytes, over 1 billion

Terabyte (T) : 240 bytes, over 1 trillion

JEDEC

assumed whenever

discussing memory


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Architecture IECE 3710

reading:

1.V1.Ch1.7-9,Ch2.1-22. V1.Ch3.1, V2.Ch1.1-2,Ch2.1


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One time a cop pulled me over for runninga stop sign. He said, "Didn't you see the

stop sign?" I said, "Yeah, but I don't believeeverything I read."

- Steven Wright


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don’t make millions of years of evolution a waste of time, eh?

why you should read:


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lecture notes != abridged version of text

next week: assembly and I/O


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CPU Memory(RAM, ROM)

Peripherals

(monitor,

printer, etc.)

Address bus

Data bus

address: how computers know where to get/store

i f ti

unidirectional

bidirectional

buses: how information is moved(#wires != #bits)

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