Memori Utama: DRAM & SRAM

Memori Utama: DRAM & SRAM Organisasi Sistem Komputer Priyanto E"mail ':'[email protected]'

Program'Studi'Pendidikan'Teknik'Elektronika' Jurusan'Pendidikan'Teknik'Elektronika' FT'UNY''2015'

Memori'dapat'menyediakan'' penyimpanan'informasi'(data)'untuk'dipanggil' kembali'(recall)'di'masa'depan'

Organisasi'Sistem'Komputer"Memori'Internal'

2'

•  Memori''terdiri'dari'sejumlah'sel''atau'lokasi'dan'seOap'sel'' meyimpan'informasi'(data'dan'prgram).' •  Seluruh'sel'dalam'memori'berisi'jumlah'bit'yang'sama.' •  Saat'ini'komputer'memiliki'standart'sel'8'bit'(byte).' •  SeOap'sel'memiliki'nomor'yang'disebut'alamat,'dimana' program'dapat'mengacu'pada'alamat'tersebut.' •  Bila'memori'memiliki'n'sel,'akan'memiliki'alamat'dari'0'' sampai'n"1.' •  Jika'memori'memiliki'm'bit'saluran'alamat,'jumlah'sel'' maksikum'yang'dapat'dialamaO'adalah'2m.' Organisasi'Sistem'Komputer"Memori'Internal'

3'

1 1 1 1 1

0 1 1 1 1

0 0 1 0 0

0 0 1 0 1

1 1 1 1 1

1 1 1 1 0

1 1 0 1 1

1 1 0 1 1

1 1 1 0 1 1 1 1 1 1 0 1 1 1 1 1 0 0 0 1 1 1 0 1

7 6 5 4 3 2 1 0 Address

D7 D6 D5 D4 D3 D2 D1 D0

A0 A1 A2 0 0 0 0 1 1 1 1

0 0 1 1 0 0 1 1


0 1 0 1 0 1 0 1 4'


5'


6'

2$%ngkat$ Main$ Memory$

Register$

Secondary$ Memory$

3$%ngkat$

Register$

Cache$ Memory$

Main$ Memory$

Secondary$ Memory$


7'


8'

•  Memori'semikonductor'digolongkan'menjadi' dua'Ope'utama:'' –  vola%le$ –  non:vola%le.''

•  Vola%le$memories'(SRAM'&'DRAM)'!'data' hilang'apabila'power'supply'maO.' •  Non:vola%le$memories'(ROM)'dapat' menyimpan'data'walaupun'catu'daya'dimaOkan.'


9'

Volatile

Non-Volatile

RAM SRAM 1970 by Intel

ROM

DRAM

Mask ROM

PROM

1970 by Intel

1970'by'Intel'

EPROM

EEPROM

1971'by'Intel'

Conventional 1979 by Intel

FLASH 1984 by Toshiba


10'


11'

•  Random'Access'Memory'(RAM)'adalah'memori'volaOle' yang'dapat'dibaca'dan'ditulisi'' •  IsOlah'akses'acak'berarO'bahwa'pengguna'dapat' mengakses'seOap'lokasi'dari'seluruh'memori'dan'dalam' urutan'apa'pun.' •  RAM'dibagi'menjadi'dua:' •  Dynamic'RAM'(DRAM) '!'seOap'bit'disimpan'dalam' kapasitor'kecil' •  StaOc'RAM'(SRAM)' '!'seOap'bit'disimpan'dalam'flip" flop' Organisasi'Sistem'Komputer"Memori'Internal'

12'

DRAM$ •  Kecepatan'rendah' •  komponen'internal'sedikit' (kapasitor)'

SRAM$ •  Kecepatan'Onggi'!'10'kali' DRAM' •  komponen'internal'lebih' banyak'(flip"flop)'

•  High'density'!'kapasitas' per'chip'lebih'besar'(4'kali' SRAM)'

•  Low'density'!'kapasitas'per' chip'lebih'kecil'' (1/4'DRAM)'

•  Memerlukan'refresh' •  Murah'

•  Tidak'memerlukan'refresh' •  Mahal'!'biaya'per'bit'4'kali' DRAM'

•  untuk'memori'utama'

•  untuk'cache'memory' Organisasi'Sistem'Komputer"Memori'Internal'

13'


14'

•  Informasi'(bit)'dalam'DRAM'disimpan'di' dalam'kapasitor'kecil' •  Isi'di'dalam'kapasitor'kecil'tersebut' akan'cepat'hilang'karena'kebocoran.'''

Column$ Row$

•  Akibatnya'tegangan'pada'ujung' Transistor$ kapasitor'jatuh'pada'OOk'yang'Odak'lagi' Storage$ mencerminkan'informasi'yang' Capacitor$ disimpan.'' •  Untuk'menghindari'hilangnya'data'perlu' melakukan'Refresh'secara'periodik' Organisasi'Sistem'Komputer"Memori'Internal'

15'

Column$$ (Data)$

•  Refresh'dilakukan'dengan'cara:' –  Membaca'tegangan'pada'seOap'sel' –  Memperkuat' –  Mengisi'kapasitor'kembali'dengan' tegangan'yang'asli'

•  Refresh'!'Read'&'Write'back'

Row$ (Address)$ Transistor$ Storage$ Capacitor$

•  Proses'ini'harus'diulangi'secara' periodik'' Organisasi'Sistem'Komputer"Memori'Internal'

16'


17'


18'


19'

Conventional DRAM

Organisasi'Sistem'Komputer"Memori' Internal'

20'

Conventional DRAM


21'

Conventional DRAM


22'

Conventional DRAM


23'

Conventional DRAM


24'

Conventional DRAM


25'

•  Fast'Page'Mode'(FPM)' •  Extended'Data"Out'(EDO)' •  Synchronous'DRAM'(SDRAM)' •  Rambus'DRAM'(RDRAM)' •  DDR'(Double'Data'Rate)'SDRAM'


26'

•  Fast'Page'Mode'(FPM)'shortens'cycle'Ome'by'allowing' processor'to'use'the'same'row'address,'but'a'different' column'address'(removes'one'step'in'the'addressing' sequence)' •  The'data'of'a'single'row'is'referred'to'as'a'"page"' •  Extended'Data"Out'(EDO)'allows'the'processor'to'overlap' the'data'read'cycle'with'the'write'for'the'next'column' address' •  EDO'result'is'a'savings'of'approximately'10'ns'for'each'read' within'a'single'page'

Access'is'synchronized'with'an'external'clock' Address'is'presented'to'RAM' RAM'finds'data'(CPU'waits'in'convenOonal'DRAM)' Since'SDRAM'moves'data'in'Ome'with'system'clock,'CPU' knows'when'data'will'be'ready' •  CPU'does'not'have'to'wait,'it'can'do'something'else' •  Burst'mode'allows'SDRAM'to'set'up'stream'of'data'and'fire' it'out'in'block' •  DDR"SDRAM'sends'data'twice'per'clock'cycle'(leading'&' trailing'edge)' •  •  •  • 

•  Suggests'transfer'rates'from'1.6'to'10.7'GBytes'per' second.'' •  Subsystem'consists'of'the'memory'array,'the'RAM' controller,'and'a'well"defined'bus' •  Bus'definiOon'includes'all'components'including'the' microprocessor'and'any'other'devices'that'may'use'it' •  VerOcal'package'(all'pins'on'one'side)'called'Rambus'in" line'memory'modules'(RIMMs)'' •  Adopted'by'Intel'for'PenOum'&'Itanium'

Tipe$

Max$Clock$ Bus$ Peak$ Tahun$ Rate$ Width$ Bandwidth$

Volts$

FPM'

1990'

25'MHz'

64'bits'

200'MBps'

5'

EDO'

1994'

40'MHz'

64'bits'

320'MBps'

5'

SDRAM'

1996'

133'MHz'

64'bits'

1.1'GBps'

3.3'

RDRAM'

1998'

400'MHz'(x2)'

16'bits'

800'MBps'

2.5'

DDR'SDRAM'

2000'

266'MHz'(x2)'

64'bits'

4.2'GBps'

2.5'

DDR2'SDRAM'

2003'

533'MHz'(x2)'

64'bits'

8.5'GBps'

1.8'

DDR'3'SDRAM'

2007'

800'MHz'(x2)'

64'bits'

12.8'GBps'

1.5'

DDR4'SDRAM'

2012'

1600'MHz'(x2)' 64'bits'

25.6'GBps'

1.2'


30'


31'

VDD

VDD

VDD

•  SRAM'menyimpan' nilai'biner' menggunakan' rangkaian'flip:flop.'

ΔI

WORD

L

H

•  SRAM'menyimpan' data'selama'masih' tersambung'dengan' catu'daya''

WORD VDD

I BIT

BIT


32'


33'


34'

A0 A1 D0..D7 CS R/W

Bagaimana'membangun'memori'16'byte?'


35'

Diperlukan rangkaian DECODER 2 ke 4

A3$

A2$

A1$

A0$

0'

0'

0'

0'

0'

0'

0'

1'

0'

0'

1'

0'

0'

0'

1'

1'

0'

1'

0'

0'

0'

1'

0'

1'

0'

1'

1'

0'

0'

1'

1'

1'

1'

0'

0'

0'

1'

0'

0'

1'

1'

0'

1'

0'

1'

0'

1'

1'

1'

1'

0'

0'

1'

1'

0'

1'

1'

1'

1'

0'

1'

1'

1'

1'


36'

A1' A0' D0..D7'

ME'

0..3'

2 to 4 Decoder

A3' A2'

4..7'

R/W

8..11'

Memori'4x4'byte' membentuk'satu' memori'16'byte'

12..15' Organisasi'Sistem'Komputer"Memori'Internal'

37'


38'

Dari'mana'' angka'8'KB?' Organisasi'Sistem'Komputer"Memori'Internal'

39'


40'


41'

•  Dalam'sistem'komputer,'SRAM'digunakan'sebagai' cache%memory% •  Cache'memory,'digunakan'untuk'menyimpan' instruksi'atau'data'yang'sering'digunakan'oleh'CPU.' •  Untuk'komputer'yang'memiliki'cache%memory%dua' level,'SRAM'digunakan'untuk'cache'level'2'(di'luar)' CPU.' •  Cache'level'1'teknologinya'sama'dengan'SRAM,' tetapi'ditanam'di'dalam'CPU''


42'


43'

•  Read"only'memory'(ROM)'berisikan'suatu'pola'data' permanen'yang'Odak'dapat'diubah.'' •  ROM'adalah'nonvola-le;'yaitu,'Odak'memerlukan' sumber'daya'untuk'mempertahankan'nilai"nilai'bit' dalam'memori.'' •  Meskipun'dimungkinkan'untuk'membaca'ROM,' namun'Odak'mungkin'untuk'menulis'data'baru'ke' dalamnya.' •  ROM:'sekali'tulis,'dibaca'berkali"kali'


44'

Permanent'storage'(nonvolaOle)'' !'listrik'maO,'data'Odak'hilang' Aplikasi' •  Microprogramming' •  Library'subrouOnes' •  Systems'programs'(BIOS)'

45'


•  Di'dalam'CPU'terdapat' Control'Unit'(CU).'' •  CU'merubah'instruksi' menjadi'sinyal'kontrol' melalui'microprogram' yang'disimpan'di'dalam' Control$ROM.' Organisasi'Sistem'Komputer"Memori'Internal'

46'

•  BIOS'juga'dikenal'dengan'System$BIOS,'ROM$BIOS' atau'PC$BIOS$'adalah'suatu'bentuk'firmware'yang' digunakan'selama'proses'boo-ng'(power"on'startup)'' •  BIOS'adalah'program'independen'yang'tersimpan' dalam'sebuah'chip'ROM'pada'motherboard'yang' digunakan'selama'proses'boo-ng'untuk'tugas"tugas' seperO'menginisialisasi'hardware'dan'memuat' kernel'ke'memori.'


47'


48'

•  Ditulis'(diprogram)'selama'pembuatan' –  Sangat'mahal'untuk'jumlah'kecil'

•  Programmable'(sekali)' –  PROM' –  Membutuhkan'peralatan'khusus'untuk'memprogram'

•  Read'“mostly”'!'ditulis'secara'elektrik' –  Erasable'Programmable'(EPROM)'!Dihapus'dengan'sinar'UV' –  Electrically'Erasable'(EEPROM)' '!Dihapus'secara'elektrik' –  Flash'memory '!Dihapus'secara'elektrik' 49'


•  PROM$(programmable$read:only$memory)'is' a'memory'chip'on'which'data'can'be'wripen' only'once.'' •  Once'a'program'has'been'wripen'onto'a' PROM,'it'remains'there'forever.'' •  Unlike'main'memory,'PROMs'retain'their' contents'when'the'computer'is'turned'off.'


50'

•  Jika'saklar'ON'dioda'hadir'di'sel'itu,'muatan'akan'dihubungkan'ke'Ground,' sel'akan'dibaca'sebagai'nilai'1.'' •  Jika'skalr'OFF,'Odak'ada'dioda'yang'menghubungkan'kolom'ke'baris,'nilai'sel' adalah'0.'Jadi'muatan'pada'kolom'Odak'bisa'ditransfer'ke'baris.' Organisasi'Sistem'Komputer"Memori'Internal'

51'

•  EPROM$(erasable$programmable$read: only$memory)'is'a'special'type'of'PROM' that'can'be'erased'by'exposing'it'to' ultraviolet'light.'' •  Once'it'is'erased,'it'can'be' reprogrammed.'' •  An'EEPROM'is'similar'to'a'PROM,'but' requires'only'electricity'to'be'erased.''


52'

•  EEPROM$(electrically$erasable$programmable$read:only$ memory).'Pronounced'e"e"prom,'an'EEPROM'is'a'special' type'of'PROM'that'can'be'erased'by'exposing'it'to'an' electrical'charge.'' •  Like'other'types'of'PROM,'EEPROM'retains'its'contents'even' when'the'power'is'turned'off.'Also'like'other'types'of'ROM,' EEPROM'is'not'as'fast'as'RAM.'' •  A'special'type'of'EEPROM,'referred'to'as'flash'memory'or' flash'EEPROM,'can'be'rewripen'while'it'is'in'the'computer' rather'than'requiring'a'special'device'called'a'PROM'reader.' This'is'what'most'of'you'will'have.' Organisasi'Sistem'Komputer"Memori'Internal'

53'

EEPROM'

Flash'EEPROM'

Bit$by$bit$erase$ Bit$line$

Block$Erase$

Select:$Line$

Block Word$Line$

16KB, 64KB… Organisasi'Sistem'Komputer"Memori'Internal'

54'


55'


56'

Memori Utama: DRAM & SRAM

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