Organi sasi Komputer Dosen Pembimbing : Khairil Anwar, ST SMIK-LPWN HAMZANWADI PANCOR
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Transcript of Organi sasi Komputer Dosen Pembimbing : Khairil Anwar, ST SMIK-LPWN HAMZANWADI PANCOR
Organisasi KomputerDosen Pembimbing : Khairil Anwar, ST
SMIK-LPWN HAMZANWADI PANCOR
Materi 3Bus-Bus Sistem
Konsep Program
Sistem hardware tidak fleksibelTujuan umum hardware untuk melakukan tugas-tugas yang berbeda, dengan jalan memberikan koresksi sinyal kontrolDengan mengubah hubungan (re-wiring),berarti memberikan set sinyal kontrol baru
Apa itu program?
Suatu urutan langkah-langkah kerjaUntuk tiap langkah, suatu operasi aritmatik atau logika dilakukanUntuk tiap operasi, dibutuhkan pengaturan sinyal kontrol yang berbeda
Fungsi Unit Kontrol
Biasanya setiap operasi mempunyai kode yang unik
Misal ADD, MOVE
Suatu bagian hardware menerima kode dan mengirimkan sinyal kontrol
We have a computer!
Komponen - komponenUnit Kontrol dan ALU merupakan bagian yang terdapat dalam CPU (Central Processing Unit)Data and instruksi perlu dimasukkan ke dalam sistem untuk mendapatkan suatu keluaran
Input/outputMedia penyimpanan sementara (temporary storage) kode and hasil proses diperlukan
Memori utama
Komponen Komputer :Top Level View
Putaran instruksi
Dua langkah:FetchExecute
Putaran Fetch
Program Counter (PC) menyimpan alamat instruksi berikutnya untuk di fetchProsessor mem-fetch-kan instruksi dari lokasi memori yang ditunjuk oleh PCPeningkatan PCInstruksi dikirim ke Instruction Register (IR)Prosessor menginterpretasikan instruksi dan melakukan aksi yang diperlukan
Putaran EksekusiProcessor-memory
Data ditransfer antara CPU dan memori utama
Processor I/OData ditransfer antara CPU dan modul I/O
Data processingBeberapa operasi aritmatik dan logika terhadap data
ControlMengatur urutan-urutan operasiMisalnya jump
Kombinasi proses di atas
Contoh Eksekusi Program
Putaran Instruksi - State Diagram
InterupsiMekanisme oleh modul-modul lainnya (mis. I/O) untuk mengubah urutan normal proses yang berlangsungProgram
Misal : overflow, division by zero
TimerDihasilkan oleh internal processor timerDigunakan dalam pre-emptive multi-tasking
I/ODari pengontrol I/O
Hardware failureMisalnya bit paritas memori error
Program Flow Control
Lingkaran InterruptDitambahkan ke dalam putaran instruksiProsessor mencek adanya interrupt
Diindikasikan oleh suatu interrupt signalJika tidak ada interrupt, fetch instruksi berikutnyaJika interrupt ditunda:
Sedang mengksekusi program Save contextSeting PC untuk memulai alamat interrupt handler routineProses interruptKembalikan context dan lanjtkan program yang di interrupt
Putaran Instruction (dengan Interrupts) - State Diagram
Multiple InterruptsDisable interrupts
Processor will ignore further interrupts whilst processing one interruptInterrupts remain pending and are checked after first interrupt has been processedInterrupts handled in sequence as they occur
Define prioritiesLow priority interrupts can be interrupted by higher priority interruptsWhen higher priority interrupt has been processed, processor returns to previous interrupt
Multiple Interrupts - Sequential
Multiple Interrupts - Nested
Connecting
All the units must be connectedDifferent type of connection for different type of unit
MemoryInput/OutputCPU
Memory Connection
Receives and sends dataReceives addresses (of locations)Receives control signals
ReadWriteTiming
Input/Output Connection(1)
Similar to memory from computer’s viewpointOutput
Receive data from computerSend data to peripheral
InputReceive data from peripheralSend data to computer
Input/Output Connection(2)
Receive control signals from computerSend control signals to peripherals
e.g. spin disk
Receive addresses from computere.g. port number to identify peripheral
Send interrupt signals (control)
CPU Connection
Reads instruction and dataWrites out data (after processing)Sends control signals to other unitsReceives (& acts on) interrupts
Buses
There are a number of possible interconnection systemsSingle and multiple BUS structures are most commone.g. Control/Address/Data bus (PC)e.g. Unibus (DEC-PDP)
What is a Bus?
A communication pathway connecting two or more devicesUsually broadcast Often grouped
A number of channels in one buse.g. 32 bit data bus is 32 separate single bit channels
Power lines may not be shown
Data Bus
Carries dataRemember that there is no difference between “data” and “instruction” at this level
Width is a key determinant of performance
8, 16, 32, 64 bit
Address bus
Identify the source or destination of datae.g. CPU needs to read an instruction (data) from a given location in memoryBus width determines maximum memory capacity of system
e.g. 8080 has 16 bit address bus giving 64k address space
Control Bus
Control and timing informationMemory read/write signalInterrupt requestClock signals
Bus Interconnection Scheme
Big and Yellow?
What do buses look like?Parallel lines on circuit boardsRibbon cablesStrip connectors on mother boards• e.g. PCI
Sets of wires
Single Bus Problems
Lots of devices on one bus leads to:Propagation delays• Long data paths mean that co-ordination of
bus use can adversely affect performance• If aggregate data transfer approaches bus
capacity
Most systems use multiple buses to overcome these problems
Traditional (ISA)(with cache)
High Performance Bus
Bus Types
DedicatedSeparate data & address lines
MultiplexedShared linesAddress valid or data valid control lineAdvantage - fewer linesDisadvantages
• More complex control• Ultimate performance
Bus Arbitration
More than one module controlling the buse.g. CPU and DMA controllerOnly one module may control bus at one timeArbitration may be centralised or distributed
Centralised Arbitration
Single hardware device controlling bus access
Bus ControllerArbiter
May be part of CPU or separate
Distributed Arbitration
Each module may claim the busControl logic on all modules
Timing
Co-ordination of events on busSynchronous
Events determined by clock signalsControl Bus includes clock lineA single 1-0 is a bus cycleAll devices can read clock lineUsually sync on leading edgeUsually a single cycle for an event
Synchronous Timing Diagram
Asynchronous Timing Diagram
PCI Bus
Peripheral Component InterconnectionIntel released to public domain32 or 64 bit50 lines
PCI Bus Lines (required)Systems lines
Including clock and reset
Address & Data32 time mux lines for address/dataInterrupt & validate lines
Interface ControlArbitration
Not sharedDirect connection to PCI bus arbiter
Error lines
PCI Bus Lines (Optional)Interrupt lines
Not shared
Cache support64-bit Bus Extension
Additional 32 linesTime multiplexed2 lines to enable devices to agree to use 64-bit transfer
JTAG/Boundary ScanFor testing procedures
PCI Commands
Transaction between initiator (master) and targetMaster claims busDetermine type of transaction
e.g. I/O read/write
Address phaseOne or more data phases
PCI Read Timing Diagram
PCI Bus Arbitration
Foreground Reading
Stallings, chapter 3 (all of it)www.pcguide.com/ref/mbsys/buses/
In fact, read the whole site!www.pcguide.com/