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(yè)數(shù): 53/153頁(yè)
文件大?。?/td> 838K
代理商: AM79C974KCW
第1頁(yè)第2頁(yè)第3頁(yè)第4頁(yè)第5頁(yè)第6頁(yè)第7頁(yè)第8頁(yè)第9頁(yè)第10頁(yè)第11頁(yè)第12頁(yè)第13頁(yè)第14頁(yè)第15頁(yè)第16頁(yè)第17頁(yè)第18頁(yè)第19頁(yè)第20頁(yè)第21頁(yè)第22頁(yè)第23頁(yè)第24頁(yè)第25頁(yè)第26頁(yè)第27頁(yè)第28頁(yè)第29頁(yè)第30頁(yè)第31頁(yè)第32頁(yè)第33頁(yè)第34頁(yè)第35頁(yè)第36頁(yè)第37頁(yè)第38頁(yè)第39頁(yè)第40頁(yè)第41頁(yè)第42頁(yè)第43頁(yè)第44頁(yè)第45頁(yè)第46頁(yè)第47頁(yè)第48頁(yè)第49頁(yè)第50頁(yè)第51頁(yè)第52頁(yè)當(dāng)前第53頁(yè)第54頁(yè)第55頁(yè)第56頁(yè)第57頁(yè)第58頁(yè)第59頁(yè)第60頁(yè)第61頁(yè)第62頁(yè)第63頁(yè)第64頁(yè)第65頁(yè)第66頁(yè)第67頁(yè)第68頁(yè)第69頁(yè)第70頁(yè)第71頁(yè)第72頁(yè)第73頁(yè)第74頁(yè)第75頁(yè)第76頁(yè)第77頁(yè)第78頁(yè)第79頁(yè)第80頁(yè)第81頁(yè)第82頁(yè)第83頁(yè)第84頁(yè)第85頁(yè)第86頁(yè)第87頁(yè)第88頁(yè)第89頁(yè)第90頁(yè)第91頁(yè)第92頁(yè)第93頁(yè)第94頁(yè)第95頁(yè)第96頁(yè)第97頁(yè)第98頁(yè)第99頁(yè)第100頁(yè)第101頁(yè)第102頁(yè)第103頁(yè)第104頁(yè)第105頁(yè)第106頁(yè)第107頁(yè)第108頁(yè)第109頁(yè)第110頁(yè)第111頁(yè)第112頁(yè)第113頁(yè)第114頁(yè)第115頁(yè)第116頁(yè)第117頁(yè)第118頁(yè)第119頁(yè)第120頁(yè)第121頁(yè)第122頁(yè)第123頁(yè)第124頁(yè)第125頁(yè)第126頁(yè)第127頁(yè)第128頁(yè)第129頁(yè)第130頁(yè)第131頁(yè)第132頁(yè)第133頁(yè)第134頁(yè)第135頁(yè)第136頁(yè)第137頁(yè)第138頁(yè)第139頁(yè)第140頁(yè)第141頁(yè)第142頁(yè)第143頁(yè)第144頁(yè)第145頁(yè)第146頁(yè)第147頁(yè)第148頁(yè)第149頁(yè)第150頁(yè)第151頁(yè)第152頁(yè)第153頁(yè)
P R E L I M I N A R Y
AMD
53
Am79C974
The oscillator requires an external 0.01% timing refer-
ence. The accuracy requirements, if an external crystal
is used are tighter because allowance for the on-board
parasitics must be made to deliver a final accuracy of
0.01%.
Transmission is enabled by the controller. As long as the
ITXEN request remains active, the serial output of the
controller will be Manchester encoded and appear at
DO
±
. When the internal request is dropped by the con-
troller, the differential transmit outputs go to one of two
idle states, dependent on TSEL in the Mode Register
(CSR15, bit 9):
TSEL LOW:
The idle state of DO
±
yields “ZERO”
differential to operate transformer-
coupled loads.
TSEL HIGH: In this idle state, DO+ is positive with
respect to DO– (logical HIGH).
Receiver Path
The principal functions of the Receiver are to signal the
Am79C974 controller that there is information on the re-
ceive pair, and separate the incoming Manchester en-
coded data stream into clock and NRZ data.
The Receiver section (see Receiver Block Diagram)
consists of two parallel paths. The receive data path is a
ZERO threshold, wide bandwidth line receiver. The car-
rier path is an offset threshold bandpass detecting line
receiver. Both receivers share common bias networks
to allow operation over a wide input common
moderange.
18681A-23
Noise
Reject
Filter
Data
Receiver
Carrier
Detect
Circuit
Manchester
Decoder
IRXDAT*
ISRDCLK*
IRXCRS*
DI
±
*Internal signal
Figure 19
.
Receiver Block Diagram
Input Signal Conditioning
Transient noise pulses at the input data stream are re-
jected by the Noise Rejection Filter. Pulse width rejec-
tion is proportional to transmit data rate, (which is fixed
at 10 MHz for Ethernet but could be different for proprie-
tary networks). DC inputs more negative than minus
100 mV are also surpressed.
The Carrier Detection circuitry detects the presence of
an incoming data frame by discerning and rejecting
noise from expected Manchester data, and controls the
stop and start of the phase-lock loop during clock acqui-
sition. Clock acquisition requires a valid Manchester bit
pattern of 1010b to lock onto the incoming message.
When input amplitude and pulse width conditions are
met at DI
±
, the internal enable signal from the MENDEC
to controller (IRXCRS) is asserted and a clock acquisi-
tion cycle is initiated.
Clock Acquisition
When there is no activity at DI
±
(receiver is idle), the re-
ceive oscillator is phase locked to internal transmit
clock. The first negative clock transition (bit cell center of
first valid Manchester “0”) after IRXCRS is asserted in-
terrupts the receive oscillator. The oscillator is then re-
started at the second Manchester “0” (bit time 4) and is
phase locked to it. As a result, the MENDEC acquires
the clock from the incoming Manchester bit pattern in
4bit times with a 1010b Manchester bit pattern.
The internal serial receive data clock, ISRDCLK and the
internal received data, IRXDAT, are enabled 1/4 bit time
after clock acquisition in bit cell 5. IRXDAT is at a HIGH
state when the receiver is idle (no ISRDCLK). IRXDAT
however, is undefined when clock is acquired and may
remain HIGH or change to LOW state whenever
ISRDCLK is enabled. At 1/4 bit time through bit cell 5,
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