- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄366550 > AM79C974KCW (ADVANCED MICRO DEVICES INC) PCnetTM-SCSI Combination Ethernet and SCSI Controller for PCI Systems PDF資料下載
參數(shù)資料
| 型號(hào)： | AM79C974KCW |
| 廠商： | ADVANCED MICRO DEVICES INC |
| 元件分類： | 微控制器/微處理器 |
| 英文描述： | PCnetTM-SCSI Combination Ethernet and SCSI Controller for PCI Systems |
| 中文描述： | 2 CHANNEL(S), 10M bps, LOCAL AREA NETWORK CONTROLLER, PQFP132 |
| 封裝： | PLASTIC, QFP-132 |
| 文件頁數(shù)： | 126/153頁 |
| 文件大?。?/td> | 838K |
| 代理商： | AM79C974KCW |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁第53頁第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁第62頁第63頁第64頁第65頁第66頁第67頁第68頁第69頁第70頁第71頁第72頁第73頁第74頁第75頁第76頁第77頁第78頁第79頁第80頁第81頁第82頁第83頁第84頁第85頁第86頁第87頁第88頁第89頁第90頁第91頁第92頁第93頁第94頁第95頁第96頁第97頁第98頁第99頁第100頁第101頁第102頁第103頁第104頁第105頁第106頁第107頁第108頁第109頁第110頁第111頁第112頁第113頁第114頁第115頁第116頁第117頁第118頁第119頁第120頁第121頁第122頁第123頁第124頁第125頁當(dāng)前第126頁第127頁第128頁第129頁第130頁第131頁第132頁第133頁第134頁第135頁第136頁第137頁第138頁第139頁第140頁第141頁第142頁第143頁第144頁第145頁第146頁第147頁第148頁第149頁第150頁第151頁第152頁第153頁
AMD
P R E L I M I N A R Y
126
Am79C974
18681A-66
This is optional. Use
accordingly to terminate both
ends of the SCSI Bus.
CPU
Memory
Internal
Drive
(Terminated)
Riser Card
High-Density
SCSI-2
Termination
External SCSI
Bus Cable
External
Peripheral
High-Density
SCSI-2
Connectors
Keyboard
Connector
To SCSI CLK1
and CLK2
Am79C974
To DC Power
Ferrite Bead
to PCI Bus
T
25
Mounted
High-Density
SCSI-2
Connector
T
Figure E-4. Motherboard Layout — Approach #2
Motherboard designs which place an internal and exter-
nal connector on either side of the Am79C974 are dis-
couraged since:
Two SCSI connectors are required on the mothe-
rboard—one more than what the other two ap-
proaches call for.
When the number of internal and external bus
components increase, the on-board terminators
would have to be turned off either through software
or hardware, which may be undesirable to a board
designer.
The possibility for creating stubs exists if the con-
nectors and Am79C974 are not routed correctly.
See Figure E-1 for the ideal routing scheme.
NOISE CONSIDERATIONS
Some areas of a PCI motherboard or host adapter de-
sign (which include the Am79C974) are more suscepti-
ble to noise. They are:
the 40 MHz crystal oscillator
the SCSI cables
the DC power planes
pins on the ICs, specifically the Am79C974.
Electromagnetic Interference (EMI)
There are several ways to reduce the amount of noise
present in these areas:
A 40 MHz crystal oscillator must be used in order
to have a 10 MB/s SCSI data rate. Use of this
40MHz crystal oscillator, which drives the
SCSICLK pin on the Am79C974, introduces the
possibility of unwanted high frequency compo-
nents, including harmonics, coupling with
Am79C974 signals. To help prevent this, a resistor
should be placed in series with the oscillator to
form a low pass filter with the input capacitance
(10 pF) of the SCSI CLK pin. This filter reduces the
edge rate of the clock waveform, increasing both
rise and fall times by 2ns. This removes higher
frequencies, specifically harmonics from the crystal
oscillator waveform and thus reduces the amount
of noise introduced into the Am79C974.
A ferrite bead, which is essentially an inductor,
may be used with the oscillator to prevent coupling
of higher frequencies with DC power supply sig-
nals. The ferrite bead blocks high frequency noise
while acting like a short to the DC components.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| AM79C975 | PCnet⑩-FAST III Single-Chip 10/100 Mbps PCI Ethernet Controller with Integrated PHY |
| AM79C973 | PCnet⑩-FAST III Single-Chip 10/100 Mbps PCI Ethernet Controller with Integrated PHY |
| AM79C973KCW | PCnet⑩-FAST III Single-Chip 10/100 Mbps PCI Ethernet Controller with Integrated PHY |
| AM79C975KCW | PCnet⑩-FAST III Single-Chip 10/100 Mbps PCI Ethernet Controller with Integrated PHY |
| AM79C973VCW | PCnet⑩-FAST III Single-Chip 10/100 Mbps PCI Ethernet Controller with Integrated PHY |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| AM79C975 | 制造商:AMD 制造商全稱:Advanced Micro Devices 功能描述:PCnet⑩-FAST III Single-Chip 10/100 Mbps PCI Ethernet Controller with Integrated PHY |
| AM79C975BKC\\W | 制造商:Advanced Micro Devices 功能描述: |
| AM79C975BKC\W | 制造商:Advanced Micro Devices 功能描述: |
| AM79C975BKD\\W | 制造商:Advanced Micro Devices 功能描述: |
| AM79C975BKD\W | 制造商:Advanced Micro Devices 功能描述:PCnet-FAST III Single-Chip 10/100 Mbps PCI Ethernet Controller with Integrated PHY 制造商:AMD (Advanced Micro Devices) 功能描述:PCnet-FAST III Single-Chip 10/100 Mbps PCI Ethernet Controller with Integrated PHY |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。