參數(shù)資料
型號: AM79C973KCW
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), 10M bps, LOCAL AREA NETWORK CONTROLLER, PQFP16
封裝: PLASTIC, QFP-160
文件頁數(shù): 63/304頁
文件大?。?/td> 2092K
代理商: AM79C973KCW
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頁當(dāng)前第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
63
P R E L I M I N A R Y
Figure 30. FIFO Burst Write At End Of Unaligned
Buffer
The exact number of total transfer cycles in the bus
mastership period is dependent on all of the following
variables: the settings of the FIFO watermarks, the
conditions of the FIFOs, the latency of the system bus
to the Am79C973/Am79C975 controller
s bus request,
and the speed of bus operation. The TRDY response
time of the memory device will also affect the number
of transfers, since the speed of the accesses will affect
the state of the FIFO. During accesses, the FIFO may
be filling or emptying on the network end. For example,
on a receive operation, a slower TRDY response will
allow additional data to accumulate inside of the FIFO.
If the accesses are slow enough, a complete DWord
may become available before the end of the bus mas-
tership period and, thereby, increase the number of
transfers in that period. The general rule is that the
longer the Bus Grant latency, the slower the bus trans-
fer operations; the slower the clock speed, the higher
the transmit watermark; or the lower the receive water-
mark, the longer the total burst length will be.
When a FIFO DMA burst operation is preempted, the
Am79C973/Am79C975 controller will not relinquish
bus ownership until the PCI Latency Timer expires.
Buffer Management Unit
The Buffer Management Unit (BMU) is a microcoded
state machine which implements the initialization pro-
cedure and manages the descriptors and buffers. The
buffer management unit operates at half the speed of
the CLK input.
Initialization
Am79C973/Am79C975 initialization includes the read-
ing of the initialization block in memory to obtain the op-
erating parameters. The initialization block can be
organized in two ways. When SSIZE32 (BCR20, bit 8)
is at its default value of 0, all initialization block entries
are logically 16-bits wide to be backwards compatible
with the Am79C90 C-LANCE and Am79C96x PCnet-
ISA family. When SSIZE32 (BCR20, bit 8) is set to 1, all
initialization block entries are logically 32-bits wide.
Note that the Am79C973/Am79C975 controller always
performs 32-bit bus transfers to read the initialization
block entries. The initialization block is read when the
INIT bit in CSR0 is set. The INIT bit should be set be-
fore or concurrent with the STRT bit to insure correct
operation. Once the initialization block has been com-
pletely read in and internal registers have been up-
dated, IDON will be set in CSR0, generating an
interrupt (if IENA is set).
The Am79C973/Am79C975 controller obtains the start
address of the initialization block from the contents of
CSR1 (least significant 16 bits of address) and CSR2
(most significant 16 bits of address). The host must
write CSR1 and CSR2 before setting the INIT bit. The
initialization block contains the user defined conditions
for Am79C973/Am79C975 operation, together with the
base addresses and length information of the transmit
and receive descriptor rings.
There is an alternate method to initialize the
Am79C973/Am79C975 controller. Instead of initializa-
tion via the initialization block in memory, data can be
written directly into the appropriate registers. Either
method or a combination of the two may be used at the
discretion of the programmer. Please refer to
Appendix
A, Alternative Method for Initialization
for details on this
alternate method.
Re-Initialization
The transmitter and receiver sections of the
Am79C973/Am79C975 controller can be turned on via
the initialization block (DTX, DRX, CSR15, bits 1-0).
The states of the transmitter and receiver are moni-
tored by the host through CSR0 (RXON, TXON bits).
The Am79C973/Am79C975 controller should be re-ini-
tialized if the transmitter and/or the receiver were not
turned on during the original initialization, and it was
subsequently required to activate them or if either sec-
tion was shut off due to the detection of an error condi-
tion (MERR, UFLO, TX BUFF error).
FRAME
CLK
AD
IRDY
TRDY
C/
BE
DEVSEL
REQ
GNT
1
2
3
4
5
6
7
0000
0111
PAR
PAR
PAR
PAR
DEVSEL
is sampled
1110
PAR
DATA
DATA
DATA
ADD
21510D-35
相關(guān)PDF資料
PDF描述
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
AM79C975VCW PCnet⑩-FAST III Single-Chip 10/100 Mbps PCI Ethernet Controller with Integrated PHY
AM79C976 PCnet-PRO⑩ 10/100 Mbps PCI Ethernet Controller
AM79C976KIW PCnet-PRO⑩ 10/100 Mbps PCI Ethernet Controller
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AM79C973VCW 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
AM79C974 制造商:AMD 制造商全稱:Advanced Micro Devices 功能描述:PCnetTM-SCSI Combination Ethernet and SCSI Controller for PCI Systems
AM79C974KC 制造商:Advanced Micro Devices 功能描述:
AM79C974KC/W 制造商:未知廠家 制造商全稱:未知廠家 功能描述:LAN Node Controller