Transcript
12063122-005
M.Ayyaz idrees
12063122-063
M.Bilal Akram
12063122-059
M.Zeeshan
12063122-091
Ihtishaam hussain
12063122-081
Taimoor Kamil
Group #5
University Of Gujrat
BUS INTERFACE
BUS
Interface
o Lines used to Exchange
data between different
components of
computer .
o Systems require custom
interface connected to
one of bus.
Types
Industrial
standard
architecture
bus
(ISA)
Peripheral
component
Interconnect
(PCI) bus
Universal
serial bus
(USB)
Advanced
graphics
port
(AGP)
The Industrial
standard
architecture bus
• Evolved from original 8-bit
standard to 16-bit standard
• Vanished in home systems now a
days but found in industrial
systems due to low cost
• Nowadays 32 bit version used
“extended ISA”
The 8-bit ISA Bus output Interface
1 GND IO CHK
2 RESET D7
3 +5V D6
4 IRQ9 D5
5 -5V D4
6 DRQ2 D3
7 -12V D2
8 OWS D1
9 +12V D0
8-BIT ISA BUS
12 MEMR A19
13 IOW A18
14 IOR A17
15 DACK3 A16
16 DRQ3 A15
17 DACK1 A14
18 DRQ1 A13
19 DACK0 A12
20 CLOCK A11
21 IRQ7 A10
22 IRQ6 A9
23 IRQ5 A8
24 IRQ4 A7
25 IRQ3 A6
26 DACK2 A5
27 T/C A4
10 GND IO RDY
11 MEMW AEN
For controlling
I/O and
memory
• DACK0-DACK3
Acknowledge outputs
• DRQ1-DRQ3 DMA request
inputs
Interrupt Request Lines
useful for I/O interface
8-bit ISA Bus input interface
A pair of Analog to digital converter is interfaced with ISA
bus
Connections are made
through 9pin converter
Complex task because each each
converter need1 )A write pulse to
start.
2) A read pulse to read digital data
3) a pulse to enable selection of INTR
output
The 16-bit ISA Bus
• Additional connector is connected behind the 8-bit connector
• One plugs into original 8-bit connector and other to new 16-bit connector
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Parallel Printer InterfacePRESENTED BY:
IHTISHAM HUSSAIN(091)
LPT
LPT stands for line printer. The printer interface gives the user access to eight lines that can be programmed to receive or send parallel data.
Port DetailsThe parallel port (LPT1) is normally at I/O port addresses 378H, 379H, and 37AH from DOS or using a driver in Windows.
The secondary (LPT2) port, if present, is located at I/O port addresses 278H, 279H, and 27AH.
A 25-pin D-type on the back of the PC
A 36-pin Centronicson the back of the
printer
The Centronics interface implemented by the parallel port uses two connectors.
The parallel port can work as both a receiver and a transmitter at its data pins (D0–D7).This allows devices other than printers, such as CD-ROMs, to be connected to and used by the PC through the parallel port.
Table
Port 378H
The data port that connects to bits D0 – D7 (pins 2 – 9)
Port 379H
THIS IS A READ-ONLY PORT THAT RETURNS THE INFORMATION FROM THE PRINTER THROUGH SIGNALS SUCH AS BUSY, #ERROR AND SO FORTH .
It is a additional Status Port
Port 37AH
Using the Parallel Port
To read the port, it must first be initialized by sending 20H to register 37AH as illustrated..
Example:
MOV AL,20H
MOV DX,37AH
OUT DX,AL
• Once the parallel port is programmed as an input port, reading is accomplished byaccessing the data port at address 378H.
To write data to the parallel port, reprogram the command register at address 37A by writing 00H to program the bidirectional bit with a zero. Once the bidirectional bit is programmed,data are sent to the parallel port through the data port at address 378H.
12063122-059 . ZEESHAN
PCI BUS Peripheral Component Interconnect, or PCI,
is a standardized mode for connecting
peripheral devices to a computer system.
The PCI standard was proposed by Intel in
1991 and became common in 1994.
The plug-and-play feature of Windows 95
was largely responsible for the acceptance
of the PCI interface
FUNCTION
The function of PCI devices is to expand the capabilities of a
computer and allow it to perform functions it could not perform
before (such as connecting to the Internet through an internal
modem), or could perform better (as a dedicated graphics card would do).
CONFIGURATION
To utilize it, a computer must be able to locate or address a PCI
mechanism within the system's BIOS. The BIOS, or basic
input/output system, is the base program in the computer that
detects and manages all hardware devices. The PCI codes
communicate to the computer the location and functions of
each PCI mechanism. If the codes are misread or are incorrect, the system does not detect the device. The configuration of the
PCI device is recorded in the Extended System Configuration
Data, or ESCD.
PLUG AND PLAY
Windows contains a plug-and-play, or PNP, feature for hardware
devices, including PCI devices. PNP enables the system to detect
and address new hardware without the user having to manually change settings in the BIOS. If for some reason the PNP feature
does not work for a hardware component, the user can manually
enter the device in the system's BIOS setup.
DRAWBACK
One of the primary disadvantages of PCI is that you can only
connect as many devices as there are slots in your
motherboard's PCI bus. Also, PCI was superseded by PCI Express,
which is faster and benefits from serial communication between the computer and devices.
PROCESSOR CONNECTION WITH PCI
BUS
The microprocessor connects the PCI bus through an integrated
circuit called “PCI BRIDGE”
INTERFACING
Complex
PCI bus controller.
Registers, Parity block, Initiator, Target, Vendor ID EPROM as required components
COMMANDS
0000 Interrupt Acknowledge
This is a special form of read cycle implicitly addressed to the
interrupt controller.
0001 Special Cycle
Special cycle is used to transfer the data to all PCI components.
0010 I/O Read
This performs a read from I/O space.
CONTINUED
0011 I/O Write
This performs a write to I/O space.
0100-0101 Reserved
A PCI device must not respond to an address cycle with these command
codes.
0110 Memory Read
This performs a read cycle from memory space.
CONTINUED
0111 Memory Write
This operates similarly to a memory read.
1000-1001 Reserved
A PCI device must not respond to an address cycle with these
command codes.
1010 Configuration Read
This is similar to an I/O read, but reads from PCI configuration
space.
PCI BUS SIGNALS
PCI DIAGRAM
FUTURE HORIZONS
In future all computer systems may use PCI bus.
Macintosh and Apple systems are also switching to PCI bus.
(UNIVERSAL SERIAL BUS)
USB
(12063122-063) bilal
Define USB?• Stands for "Universal Serial Bus." USB is the most common type of
computer port used in today's computers. It can be used to connect
keyboards, mice, game controllers, printers, scanners, digital cameras,
and removable media drives. With the help of a few USB hubs, you can
connect up to 127 peripherals to a single USB port and use them all at
once
History:• Defined by Intel and other industry leaders
in early 1990s
• Ease of use was primary goal
Specification of USB about speed:
Data transfer speeds are 480 Mbps for full speed USB 2.0
operations, 11 Mbps for 1.1
1.5 Mbps for low speed
Limit of cable length and Power Specification of
USB:
Cable length 5m max for full speed and 3m max for low speed.
Max power through these cables is at 100 mA and max current at 5.0 V
If the amount of current exceeds 100 mA, windows will display a yellow
exclamation point next to the device, indicates a over load condition
Connectors:
USB Pins:
Pin Number Signal Front View
1 +5.0v
2 -Data
3 +Data
4 Ground
NRZI(non-return to zero, inverted):
The USB uses NRZI data encoding for transmitting packets. This
encoding method does not change the signal level for logic 1, but the
signal level is inverted for each change to a logic 0.
NRZI Encoding:
Fig. illustrate a digital data stream and the USB signal produced using this
encoding method.
Bit Stuffing:
• The actual data transmitted includes sync bits using a method
called bit stuffing.
Flow chart of bit stuffing:
USB Commands:
Know we will discuss the commands use to transfer data and select the
receptor.
There are following commands:
• PID(Packet identification byte)
• ADDR
• ENDP
• CRC
• ACK and NAK
PID:
The PID contain 8 bit, but only the right most 4 bits contain the type
of packet that follows, if any. The left most 4 bit of the PID are the
1s complementing the right most 4 bit. If a command of 1000 is
send, the actual byte send for the PID is 0111 1000.
ADDR(address field):
• The ADDR contain the 7-bit address of the USB device. As
mentioned earlier there are 127 devices present on the USB at a
time.
ENDP:
The ENDP is a 4 bit number used by the USB. Endpoint 0000 is
used for initialization; other endpoint numbers are unique to each
USB device.
CRC(cyclic redundancy checks):
There are two types of CRC used on USB.
CRC is a serial checking mechanism. Using 5bit CRC a residual of 01100
is received for no error and for 16bit CRC a residual of 100000000001101
received for no error.
5 bit CRC16 bit CRC
ACK and NAK tokens:
USB uses these tokens to coordinate the transfer of data packets
data b/w the host system and USB device.
Data transfer from host to USB device. The USB device transmit
ACK or NAK back to host.
If data received correctly the ACK sent otherwise NAK.
If host receives a NAK token it retransmits the data packet until the
receiver receives it correctly. This method is called stop and wait
flow control.
The Accelerated Graphics Port (also called Advanced Graphics Port) is a high-speed point-to-point channel for attaching a graphics card to a computer’s motherboard, primarily to assist in the acceleration of 3D computer graphics.
is an advanced port designed for Video cards and 3D accelerators. AGP introduces a dedicated point-to-point channel that allows the graphics controller direct access the system memory.
Some motherboards have been built with multiple independent AGP slots. AGP is currently being phased out in favor of PCI Express.
AGP 1x
A 32-bit channel operating at 66 MHz resulting in a maximum data rate of 266 megabytes per second (MB/s), doubled from the 133 MB/s transfer rate of PCI bus
AGP 2x
A 32-bit channel operating at 66 MHz double pumped to an effective 133 MHz resulting in a maximum data rate of 533 MB/s; signaling voltages the same as AGP 1x;
AGP 4x
A 32-bit channel operating at 66 MHz quad pumped to an effective 266 MHz resulting in a maximum data rate of 1066 MB/s (1 GB/s)
AGP 8x
A 32-bit channel operating at 66 MHz, strobing eight times per clock, delivering an effective 533 MHz resulting in a maximum data rate of 2133 MB/s (2 GB/s); 0.8 V signaling.
AGP Pro
AGP Pro is a extention to the standard AGP connector and slot on both sides to provide additional power to an AGP card.It comes in two flavors, AGP Pro110 provides for 50-110W of power and requires two adjacent PCI slots for cooling. AGP Pro50 provides for 20-50W of power and requires a single adjacent PCI slot for cooling.
Texturing: Also called Direct Memory Execute mode, allows textures to be stored in main memory.
Throughput: Various levels of throughput are offered: 1X is 266 MBps, 2X is 533 MBps; and 4X provides 1.07 GBps.
Sideband Addressing: Speeds up data transfers by sending command instructions in a separate, parallel channel.
Pipelining: Enables the graphics card to send several instructions together instead of sending one at a time.
Not all operating systems support AGP because of limited or no driver support. For example, Windows 95 did not incorporate AGP support.
=> => ?before now In the future
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