參數(shù)資料
型號: AM79C975VCW
廠商: ADVANCED MICRO DEVICES INC
元件分類: 微控制器/微處理器
英文描述: PCnet⑩-FAST III Single-Chip 10/100 Mbps PCI Ethernet Controller with Integrated PHY
中文描述: 5 CHANNEL(S), 100M bps, LOCAL AREA NETWORK CONTROLLER, PQFP176
封裝: TQFP-176
文件頁數(shù): 89/304頁
文件大?。?/td> 2092K
代理商: AM79C975VCW
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頁當(dāng)前第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頁第154頁第155頁第156頁第157頁第158頁第159頁第160頁第161頁第162頁第163頁第164頁第165頁第166頁第167頁第168頁第169頁第170頁第171頁第172頁第173頁第174頁第175頁第176頁第177頁第178頁第179頁第180頁第181頁第182頁第183頁第184頁第185頁第186頁第187頁第188頁第189頁第190頁第191頁第192頁第193頁第194頁第195頁第196頁第197頁第198頁第199頁第200頁第201頁第202頁第203頁第204頁第205頁第206頁第207頁第208頁第209頁第210頁第211頁第212頁第213頁第214頁第215頁第216頁第217頁第218頁第219頁第220頁第221頁第222頁第223頁第224頁第225頁第226頁第227頁第228頁第229頁第230頁第231頁第232頁第233頁第234頁第235頁第236頁第237頁第238頁第239頁第240頁第241頁第242頁第243頁第244頁第245頁第246頁第247頁第248頁第249頁第250頁第251頁第252頁第253頁第254頁第255頁第256頁第257頁第258頁第259頁第260頁第261頁第262頁第263頁第264頁第265頁第266頁第267頁第268頁第269頁第270頁第271頁第272頁第273頁第274頁第275頁第276頁第277頁第278頁第279頁第280頁第281頁第282頁第283頁第284頁第285頁第286頁第287頁第288頁第289頁第290頁第291頁第292頁第293頁第294頁第295頁第296頁第297頁第298頁第299頁第300頁第301頁第302頁第303頁第304頁
Am79C973/Am79C975
89
P R E L I M I N A R Y
ler, unless the EAR pin becomes active during the first
64 bytes of the frame (excluding preamble and SFD).
This allows external address lookup logic approxi-
mately 58 byte times after the last destination address
bit is available to generate the EAR signal, assuming
that the Am79C973/Am79C975 controller is not config-
ured to accept runt packets. The EADI logic only sam-
ples EAR from 2 bit times after SFD until 512 bit times
(64 bytes) after SFD. The frame will be accepted if EAR
has not been asserted during this window. In order for
the EAR pin to be functional in full-duplex mode, FDR-
PAD bit (BCR9, bit 2) needs to be set. If Runt Packet
Accept (CSR124, bit 3) is enabled, then the EAR signal
must be generated prior to the 8 bytes received, if
frame rejection is to be guaranteed. Runt packet sizes
could be as short as 12 byte times (assuming 6 bytes
for source address, 2 bytes for length, no data, 4 bytes
for FCS) after the last bit of the destination address is
available. EAR must have a pulse width of at least 110
ns.
The EADI outputs continue to provide data throughout
the reception of a frame. This allows the external logic
to capture frame header information to determine pro-
tocol type, internetworking information, and other use-
ful data.
The EADI interface will operate as long as the STRT bit
in CSR0 is set, even if the receiver and/or transmitter
are disabled by software (DTX and DRX bits in CSR15
are set). This configuration is useful as a semi-power-
down mode in that the Am79C973/Am79C975 control-
ler will not perform any power-consuming DMA opera-
tions. However, external circuitry can still respond to
control
frames on the network to facilitate remote node
control. Table 11 summarizes the operation of the EADI
interface.
External Address Detection Interface: MII Snoop
Mode
The MII Snoop mode provides all necessary data and
clock signals needed for the EADI interface. Data for
the EADI is the RXD[3:0] receive data provided to the
internal MII. The user will receive the data as 4 bit nib-
bles. RX_CLK is provided to allow clocking of the
RXD[3:0] receive nibble stream into the external ad-
dress detection logic. The RXD[3:0] data is synchro-
nous to the rising edge of the RX_CLK. The data
arrives in nibbles and can be at a rate of 25 MHz or 2.5
MHz.
The assertion of SFBD is a signal to the external ad-
dress detection logic that the SFD has been detected
and that the first valid data nibble is on the RXD[3:0]
data bus. The SFBD signal is delayed one RX_CLK
cycle from the above definition and actually signals the
start of valid data. In order to reduce the amount of
logic external to the Am79C973/Am79C975 controller
for multiple address decoding systems, the SFBD sig-
nal will go HIGH at each new byte boundary within the
packet, subsequent to the SFD. This eliminates the
need for externally supplying byte framing logic.
The EAR pin should be driven LOW by the external ad-
dress comparison logic to reject a frame.
External Address Detection Interface: Receive
Frame Tagging
The Am79C973/Am79C975 controller supports re-
ceive frame tagging in MII Snoop mode. The receive
frame tagging implementation is a two-wire chip inter-
face in addition to the existing EADI.
The Am79C973/Am79C975 controller supports up to
15 bits of receive frame tagging per frame in the receive
frame status (RFRTAG). The RFRTAG bits are in the
receive frame status field in RMD2 (bits 30-16) in 32-bit
software mode. The receive frame tagging is not sup-
ported in the 16-bit software mode. The RFRTAG field
are all zeros when either the EADISEL (BCR2, bit3) or
the RXFRTAG (CSR7, bit 14) are set to 0. When
EADISEL (BCR2, bit 3) and RXFRTAG (CSR7, bit 14)
are set to 1, then the RFRTAG reflects the tag word
shifted in during that receive frame.
In the MII Snoop mode, the two-wire interface will use
the MIIRXFRTGD and MIIRXFRTGE pins from the
EADI interface. These pins will provide the data input
and data input enable for the receive frame tagging, re-
spectively. These pins are normally not used during the
MII operation.
The receive frame tag register is a shift register that
shifts data in MSB first, so that less than the 15 bits al-
located may be utilized by the user. The upper bits not
utilized will return zeros. The receive frame tag register
is set to 0 in between reception of frames. After receiv-
ing SFBD indication on the EADI, the user can start
shifting data into the receive tag register until one net-
work clock period before the Am79C973/Am79C975
controller receives the end of the current receive frame.
In the MII Snoop mode, the user must see the RX_CLK
to drive the synchronous receive frame tag data inter-
face. After receiving the SFBD indication, sampled by
the rising edge of the RX_CLK, the user will drive the
data input and the data input enable synchronous with
the rising edge of the RX_CLK. The user has until one
network clock period before the deassertion of the
Table 11. EADI Operations
Required
Timing
No timing
requirements
No timing
requirements
PROM
EAR
Received
Frames
1
X
All received frames
0
1
All received frames
0
0
Low for two bit
times plus 10 ns
Frame rejected if in
address match
mode
相關(guān)PDF資料
PDF描述
AM79C976 PCnet-PRO⑩ 10/100 Mbps PCI Ethernet Controller
AM79C976KIW PCnet-PRO⑩ 10/100 Mbps PCI Ethernet Controller
AM79C976KCW PCnet-PRO⑩ 10/100 Mbps PCI Ethernet Controller
AM79C978AKCW Single-Chip 1/10 Mbps PCI Home Networking Controller
AM79C978AVCW Single-Chip 1/10 Mbps PCI Home Networking Controller
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AM79C976 制造商:AMD 制造商全稱:Advanced Micro Devices 功能描述:PCnet-PRO⑩ 10/100 Mbps PCI Ethernet Controller
AM79C976KC 制造商:Rochester Electronics LLC 功能描述:METRIC PLASTIC QUAD-RING - Bulk
AM79C976KCW 制造商:AMD 制造商全稱:Advanced Micro Devices 功能描述:PCnet-PRO⑩ 10/100 Mbps PCI Ethernet Controller
AM79C976KD 制造商:Advanced Micro Devices 功能描述:ETHERNET:MEDIA ACCESS CONTROLLER (MAC)
AM79C976KF 制造商:Advanced Micro Devices 功能描述:Ethernet CTLR Single Chip 10Mbps/100Mbps 3.3V 208-Pin PQFP 制造商:AMD (Advanced Micro Devices) 功能描述:Ethernet CTLR Single Chip 10Mbps/100Mbps 3.3V 208-Pin PQFP