1
P&I Ch4 - Bus 1
ch 4. I/O Interface bus overview
Giíi thiÖu bus chuÈn cho ghÐp nèi, më réng:
–ISA/ PC-104 – AT bus
–USB (Universal Serial Bus)
–Philips I2C
–PCI (Peripheral Component Interconnect)
–SCSI (Small Computer Systems Interface)
–GPIB (General Purpose Interface Bus)
–Field buses: Siemens Profibus, ASi bus, Multi
Point
–IEEE 1394
–...
P&I Ch4 - Bus 2
4.0. Kh¸i niÖm vÒ bus:
•Lµ: PCB (Printed Circuit Board), Cable (Copper/
Optic), Slot, Connector...
•Nèi nhiÒu thiÕt bÞ slave [master], dïng chung:
trong 1 thêi ®iÓm chØ cã 1 talker – 1 hoÆc nhiÒu
listener
•Bus song song (n bit) hoÆc nèi tiÕp (I2C, USB,
SSA, Profi, ASi, IEEE 1394...)
•IO Buses vs Mem/CPU/Local Buses
•Thµnh phÇn (physical lines/ time sharing):
–Address
–Data
–Control/ Status/Handshake/data check
–[Power supply]
2
P&I Ch4 - Bus 3
4.1. industry small architecture (isa) bus:
•ISA/ AT bus, 1984, IBM, PC-104 bus, Available in
Pentium, PowerPC Platforms
•§Ó ghÐp thªm c¸c card/ thiÕt bÞ I/O chuÈn víi
Mother Board, 1..12 Slots, hiÖn t¹i c¸c m¸y cã thÓ
kh«ng dïng slot
•8/ 16 bit for data transfers
•4,77 => 8,33 MHz/11.1MHz => 2.75 MWps/5.5 MWps
max, DMA 16.
•Only 1 BusMaster, CPU hoÆc DMAC, w AEN
•No data integrity, kh«ng kiÓm tra parity, IO Check
•Dïng ®Ó ghÐp víi c¸c thiÕt bÞ chËm, kiÓu ký tù:
‘character typed devices’ : keyboard, mouse...
•Refer ‘AT Technical Reference’ or TechHelp for
detail
P&I Ch4 - Bus 4
H×nh 4.1. AT/ ISA/ PC 104 bus
3
P&I Ch4 - Bus 5
Chu kỳ R/W của ISA
•Tham khảo hình cuối Ch1
P&I Ch4 - Bus 6
4.2. Universal serial bus - usb:
4
P&I Ch4 - Bus 7
4.2. Universal Serial Bus Rev. 4.2.1: Topology
•Rev.1.1:
23/09/1998
•Chia thµnh
nhiÒu Tiers
•C¸c Tiers nèi
c¸c thiÕt bÞ:
Hub hoÆc
chøc n¨ng
•Mçi Tier cã
Hub(s)
P&I Ch4 - Bus 8
4.3. usB: specifications
•ChØ cã 1 USB host (USB
Controller) trong hÖ
•Devices, cã 2 lo¹i:
•Hub, më réng thªm thiÕt bÞ nèi vµo USB
•C¸c thiÕt bÞ chøc n¨ng nh− ISDN, JoyStick, KB,
Printer, Digital Camera, Mass Storage...
•ThiÕt bÞ chuÈn interface USB theo:
•USB Protocol
•ChuÈn H® cña USB: config vµ reset
•Communication Standard
•USB Controller/ Host polls bus & initiates all data
transfer
5
P&I Ch4 - Bus 9
¦u ®iÓm:
•TÝn hiÖu vi sai ph¸t/ thu, bäc kim, chèng nhiÔu
•CRC Protection ®/v data & control fields
•Tù ph¸t hiÖn attach/ detach, x¸c ®Þnh cÊu h×nh
c¸c thiÕt bÞ tù ®éng ë møc hÖ thèng
•TimeOut ®/v tr−êng hîp mÊt gãi tin/ gãi tin lçi
P&I Ch4 - Bus 10
4.3. usB: Physical interface
•1.5 Mbps – Low speed mode vµ 12Mbps (Revision 1.1)
•Nguån cÊp +5V, vµi metre
•Power managment
•Revision 2.0: 480Mb/s