Presentation on theme: "PC System Overview OBJECTIVES: Upon completion of this topic, the participant will be able to do the following: Describe a block diagram of a PC system."— Presentation transcript:
PC System Overview OBJECTIVES: Upon completion of this topic, the participant will be able to do the following: Describe a block diagram of a PC system. Compare various Intel Processors used in PCs. Describe the basic architecture of the CPU. Describe various buses used by the CPU and discuss a basic bus transaction. Describe the organization of PC Base Memory, Reserved, and Extended Memory Areas. Find the I/O addresses of specific I/O devices.
North Bridge HOST-PCI Bridge DRAM Controller AGP Interface South Bridge (ICH) PCI-PCI Bridge 8254 Timer; 8259 Intr. Ctlr; 8237 DMAC; RTC EIDE Interface USB Ctlr Super I/O Kybd/Mouse Ctlr Floppy Ctlr Serial & IR port Parallel ports Basic operational design is called its architecture Chipset: North Bridge, South Bridge, & Firmware Hub SATA IDE USB Audio LAN KBMouseFloppySerialParallel FWHSIO South Bridge (ICH) North Bridge (GMCH) Clock Generator Processor System management bus LPC bus Host clock PCIe x16 Bus System memory PCI clock USB clock Hublink clock PCIe x1 FSB/Host Bus DMI VGA PCI Bus
Processor Year Internal Arch (register size) External Bus Size Tran- sistors Principle Features K16-bit architecture, basic segment protection KSame as 86, but with 8-bit processor bus. (IBM PC) KIntroduced protected mode, access to 16 MB memory,. Intel 386 TM K1st true 32-bit processor. Adds 32-bit reg extensions & paging,. Intel 486 TM M Adds on-chip cache, floating- point unit. Pentium® M Superscaler, Code & Data Cache, 1st 64 bit data bus 6432 Pentium® Pro M Integrated L2, Reg Renaming First P6 family processor 6432Pentium® MQuad pumped Data bus yields > 400 M trans/sec Pentium® II Pentium® III M Celeron® new instructions, Multiple Branch Prediction, Dataflow Analysis, Speculative Execution, 6432 Intel Processor Statistical Comparison
“Virtual”address space simulates more memory than actually exists by using paging to allow the excess to be stored on hard disk and copied to RAM as required. Intel Processor Statistical Comparison PC/AT Compatibility Standard Pentium ® Pentium ® Pentium ® Pentium ® Pro II MEG 16 MEG* 4 GIG * 4 GIG* 4 GIG* 64 GIG* 64 GIG* 64 GIG* NA 1 GIG 64 TERA 64 TERA 64 TERA 64 TERA 64 TERA 64 TERA On Chip On Chip On Chip On Chip On Chip 4.77, 88, 1216, 25, 3333, 5050, 60, 66 60, 66 66, /400** NO NO YES YES YES YES YESYES NO NO NO YES YES #YES #YES#YES * Protected Mode # Integrated L2 MEM SIZE D-BUS VIRTUAL SIZE CPU Addr -BUS ON CHIP CACHE # SEG. REGS MATH REG SIZE PAGING BUS SPEED ( MHz ) ** Quad pumped 100
CPU Internal Architecture Instructions are Fetched from the code cache or external bus. The Heart of the PC is the Processor The ALUs Execute the instructions. Decoded by the decode unit so the CPU can execute them. Instruction TLB/Prefetcher Front-End BTB (4K Entries) Microcode ROM Instruction Decoder Trace Cache (12K μops) Trace Cache BTB (512 Entries) μop Queue Allocator / Register Renamer Memory μop QueueInteger / Floating Point μop Queue Memory SchedulerFastSlow / General FP Scheduler Simple FP FP Register/BypassApplication Register Set FP MMX SSE SSE2 FP Move AGU Load Address AGU Store Address 2x ALU Simple Instr. 2x ALU Simple Instr. Slow ALU Complex Instr. L1 Data Cache (8Kbyte 4-way) L2 Cache (256K Byte 8-way) 48 GB/s Quad Pumped 3.2 GB/s Bus Interface Unit 256 bits 64-bits wide System Bus
CPU Signals Required for operation Multiple Power & Ground pins. Processor Reset (input): Clock (input): 66, 100, 133, 200 MHz depending on design. The CPU uses this as the external bus clock. Source Synchronous protocol uses strobes (i.e., DSTB[3:0]#) to latch data, implementing a 4X transfer rate. “Quad pumping” example: A processor using a 100MHz external clock achieves an effective 400MHz transfer rate. Address Bus A[35:3]# CPU Data Bus D[63:0]# Power Ground RESET# BCLK RS[2:0]# ADS# REQ[4:0]# DSTB[3:0]# DBI[3:0]#
Simplified Bus Introduction Microprocessors use several buses to communicate with memory and I/O resources. The Processor System Bus (PSB) or Host Bus or FSB (Front Side Bus) is the set of wires used to carry information to and from the processor. In general, buses communicate three types of information: CPU MEMORY I/O ADDRESS DATA ADS# REQ[4:0]# RS[2:0]# DSTB[3:0]# DBI[3:0]# CONTROL Address Data Control
CPU Bus Description Address bus: The number of address lines determines the amount of memory supported. The CPU address consists of two sets of signals: The CPU uses A[35:3] to identify a group of 8 locations known as a Quadword (8 bytes). Byte Enables address locations within a Quadword. BE[7:0]# -- In effect a decode of the address lines A2-A0 which the CPU does not generate. BE[7:0]# and other configuration signals appear on second packet of address phase. CPU 64 bit Memory D63:0 A[35:3], BE[7:0]# H 0000FFFFH H I/O Space 0000FFFCH Not Accessible 64 KByte
CPU Bus Description Data bus: A single transfer cycle can read or write up to 64 bits at a time (8 bytes). D63:D0 (bi-directional): 64-bit data path to/from processor. Note: This is a 32 bit CPU due to having 32 bits registers. Control bus: Typical control bus signals are these: ADS# (in/output):Address Strobe - CPU begins bus cycle. REQ[4:0]# (input/output):Request - 5-bit code to identify the type of transaction, (memory or I/O, read or write). RS[2:0]# (input):Response - 3 bit code to respond to CPU. DSTB[3:0]# (output):Data Strobe - Used to latch data. DBI[3:0]# (input/output):Data Block Inversion - Indicates current state of data bus (inverted or not).
Hyper-Threading Technology HT Technology enables a single processor to execute 2 separate code streams (called threads) concurrently HT technology allows 1 physical processor to appear as 2 “logical” processors to software (O/S and applications). Each logical processor has its own architecture state with its own set of general-purpose and control registers Some resources are shared (caches, exe units, buses, etc) Architectural State Processor Execution Resources Architectural State Processor Execution Resources Architectural State Processor Execution Resources Architectural State System Bus P6 Microarchitecture Dual Processor Intel® NetBurst™ Microarchitecture Hyper-Threading Enabled Processor HT technology can repeatedly switch from one set of data instructions to the other, every few nanoseconds.
Basic Bus Transaction A BUS CYCLE (transaction) begins when processor asserts ADS# while driving valid Address & Control signals. A BURST Cycle always transfers 512 bits (8*64) [64 bytes] CPU only needs to output starting address to fill one cache line. Burst mode is used for all Cacheable cycles. Burst transfers occur in an address region that begins on a 64-byte boundary & the system board must calculate the 2nd, 3rd, etc burst addresses. 0-8 byte transfers for non- cacheable memory and I/O are also supported. Burst mode is used for all Cacheable cycles. Burst transfers occur in an address region that begins on a 64-byte boundary & the system board must calculate the 2nd, 3rd, etc burst addresses. 0-8 byte transfers for non- cacheable memory and I/O are also supported. BCLK0 ADS# RS[2:0}# DRDY# DATA[63:0]# REQ[4:0}# A[35:3]# Addr BE Transaction type/direction Complete, Defer, Fail Address & Byte Enables Data Ready Transaction ends when DRDY# is returned to the processor.
Source Synchronous Signalling The Intel® Pentium® 4 processor supports the desktop system bus by delivering up to 6.4 Giga Bytes per second (GB/s) of data throughput. This is accomplished through a physical signaling scheme which quad pumps data transfers over a 200- MHz clocked system bus Source Synchronous Clocking sends a strobe signal in parallel with the data. (also used on Address Bus) Data and STROBE are generated at the Driver
Address Bus is Double Pumped. SP1 – Address SP2 – BE/Config Data Bus is Quad- Pumped Transfers 4 packets of data per BCLK cycle 4 x 8bytes x 200M = 6.4 GB/sec.7 BCLK (200MHz) ADSTB AD[35:3] REQ[4:0] DSTBp# DSTBn# D# Address BE / Config *SP1 SP2 5 nanoseconds * SP – Sub Phase Data/Address signals propagate toward their destinations at the same rate as accompanying strobes Processor Source Synchronous Cycle
System Memory Map For compatibility, all processors start in real mode after reset. In order to maintain compatibility with the original PC's BIOS (and the DOS operating system), the PC memory map is limited to 1M byte in REAL MODE. The original PC used an 8088 microprocessor limited the memory map to a size of 1M Byte. 1M byte ADDRESS FFFFFFFF FFFE FFF0 10FFEF FFFFF 0F0000 0EFFFF 0E0000 0DFFFF 0C0000 OBFFFF 0A FFFF DESCRIPTION 128K ROM OR DRAM EXTENDED SYSTEM MEMORY HIGH MEMORY AREA 64K ROM OR DRAM 64K ROM OR DRAM 128K I/O EXPANSION ROM 128K VIDEO RAM 640K SYSTEM MEMORY FUNCTION RESERVED FOR SYSTEM ON BOARD DRAM ROM BIOS OR RAM BIOS EXTENSION OR RAM RESERVED FOR ROM ON I/O ADAPTERS DISPLAY BUFFER REAL MODE ON BOARD DRAM
Base (Conventional) Memory 1st 640 KB of system memory is “conventional” memory. Sometimes referred to as DOS memory--refers to the memory-addressing scheme used in the original IBM and compatible PCs. The 1st 640 KB is used by: System BIOS Interrupt Vector Table: 0-300h BIOS data area: 400h-500h Operating System and application programs Interrupt Vector Table BIOS DATA 0000h 0400h 0500h 256K 512K A0000h 640K 64K 128K Operation System and Application Programs
Reserved Memory Memory from 640K-1MB is for system use and is typically not available for applications. Display adapter memory is typically on the display adapter itself. Video BIOS may be on the display adapter. 0E0000H to 0FFFFFH is reserved for BIOS. Upper 64K (F0000-FFFFF) for POST/ Runtime BIOS VGA MDA CGA VIDEO BIOS (ROM) Reserved for System BIOS POST Runtime BIOS Video Memory on VIDEO ADAPTERS (NOT System DRAM) OPTIONAL ADAPTER CARD ROMS` FFFFFh F0000h EFFFFh E0000h D0000h C8000h C7FFFh C0000h B8000h B0000h A0000h Sometimes this area is referred to as Upper Memory Blocks (UMB)
Extended Memory Memory above 1MB is called Extended Memory. PCs may come with 128M bytes or more installed. Added as an extension to the base 1 MB--the limit of memory addressability of the original PC processor (8088). Beginning with the PC/AT, it became possible to address >1MB of memory by putting the CPU in protected mode. Protected mode is used to access extended memory which is used with Windows, Unix, Linux, etc. With DOS, extended memory is typically not available at all. With the exception of the 1st 65,520 bytes (High Memory Area), extended memory is not accessible in real mode. HMA is accessible in Real Mode (usually used for DOS) using a driver which contains A20 Handler Software.
Intel IA-32 processors implement a separate I/O (input/output) space apart from memory address space. An I/O PORT is an address in I/O space in which you can read or write information (e.g., port 3F8 is a serial port ) Clearly separates Memory & I/O devices by using IN/OUT instructions for I/O, and MOV instructions for Memory transfers The size of the Intel I/O space is 64K addresses. Since the 16-bit DX register holds the address for I/O space accesses, FFFF (64K) is the max possible address. Most of the I/O assignments are industry standard. Many devices have several ports assigned to them. Some Ports such as 78/79, 90/92, 2E/2F hex are Vendor specific and are used to implement board specific features. I/O Address Map
Address (in hex) SizeDescription F E 002F , bit , bits 6: F 00A0 - 00A1 00B2 - 00B3 00C0 - 00DE 00F bytes 2 bytes 1 byte 4 bytes 1 byte 1 bit 7 bits 1 byte 16 bytes 2 bytes 31 bytes 1 byte 8 bytes DMA 1 Interrupt Controller 1 SIO Index Register SIO Data Register Timer 1 Keyboard Controller Data Byte NMI, speaker control Kbd Controller, CMD/STAT Byte Enable NMI Real Time Clock, Address Real Time Clock, Data Reserved Brd. Config. DMA Page Register Interrupt Controller 2 APM control port DMA 2 Reset Numeric Error Secondary IDE Channel Example I/O Address Map
Address (hex) SizeDescription 8 bytes 4 bytes 8 bytes 1 byte 8 bytes 4 bytes 8 bytes 6 bytes 1 byte 1 bit 7 bits 8 bytes 4 bytes 1 byte 4 bytes 8 bytes 01F0 - 01F B 02F8 - 02FF F 03BC - 03BF 03E8 - 03EF 03F0 - 03F5 03F6 03F7 (write) 03F7, bit 7 03F7, bits 6:0 03F8 - 03FF OCF8 - 0CFB 0CF9 0CFC - OCFF FF00 - FF07 Primary IDE Channel Parallel Port 2 On - Board Serial Port 2 Sec IDE Chan Cmd Port Sec IDE Chan Stat Port Parallel Port 1 Parallel Port x Serial Port 3 Floppy Channel 1 Pri IDE Chan Cmd Port Floppy Chan 1 Cmd Floppy Disk Chg Chan 1 Pri IDE Chan Status Port On - Board Serial Port 1 PCI Config Address Reg Reset Control Register PCI Config Data Reg IDE Bus Master Reg. Example I/O Address Map (Cont.)
Review & Summary PC Block diagram. PC/AT (80286) set a compatibility standard. The basic operational design is called its architecture. The Chipset consists of the North Bridge, South Bridge and Firmware Hub North Bridge: HOST-PCI Bridge / DRAM Controller. South Bridge (ICH): PCI-PCI Bridge; 8254 Timer; 8259 Intr. Ctlr 8237 DMAC; RTC; EIDE I/F; USB Ctlr Super I/O: Kybd/Mse; Floppy; Serial/IR & Parallel SATA IDE USB Audio LAN KBMouseFloppySerialParallel FWHSIO South Bridge (ICH) North Bridge (GMCH) Clock Generator Processor System management bus LPC bus Host clock PCIe x16 Bus System memory PCI clock USB clock Hublink clock PCIe x1 FSB/Host Bus DMI VGA PCI Bus
Review & Summary Basic architecture of a desktop system. The heart of a PC is the Microprocessor. Instructions are Fetched from the cache or the external bus; the decode unit Decodes instructions; ALUs Execute the instructions. Microprocessors use Address, Data, & Control buses to communicate with memory and I/O resources. A BUS CYCLE begins when the Processor asserts ADS# while driving valid Address and Control signals. Address Bus A[35:3] (includes Byte Enables BE[7:0]#) Data Bus D[63:0]: 64-bit data path to or from the processor. Control bus signals: ADS#; REQ#; RS#; DSTB#; & DBI#
Review & Summary The organization of PC Memory. The 1st 640 KB is called Conventional or Base Memory. Reserved Memory--memory from 640K to 1M byte is for system use and is not typically available for applications. Extended Memory: Memory above 1MB; CPU uses Protected Mode to access memory above 1 Mega Byte. The the organization of the PC’s I/O Address Map. The size of the Intel I/O space is 64K addresses. Intel microprocessors have a separate I/O address map. Most of the I/O assignments are industry standard.