參數(shù)資料
型號(hào): AM79C978AKCW
廠商: ADVANCED MICRO DEVICES INC
元件分類: 微控制器/微處理器
英文描述: Single-Chip 1/10 Mbps PCI Home Networking Controller
中文描述: 5 CHANNEL(S), 10M bps, LOCAL AREA NETWORK CONTROLLER, PQFP160
封裝: PLASTIC, QFP-160
文件頁(yè)數(shù): 56/256頁(yè)
文件大?。?/td> 3505K
代理商: AM79C978AKCW
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)第53頁(yè)第54頁(yè)第55頁(yè)當(dāng)前第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)第154頁(yè)第155頁(yè)第156頁(yè)第157頁(yè)第158頁(yè)第159頁(yè)第160頁(yè)第161頁(yè)第162頁(yè)第163頁(yè)第164頁(yè)第165頁(yè)第166頁(yè)第167頁(yè)第168頁(yè)第169頁(yè)第170頁(yè)第171頁(yè)第172頁(yè)第173頁(yè)第174頁(yè)第175頁(yè)第176頁(yè)第177頁(yè)第178頁(yè)第179頁(yè)第180頁(yè)第181頁(yè)第182頁(yè)第183頁(yè)第184頁(yè)第185頁(yè)第186頁(yè)第187頁(yè)第188頁(yè)第189頁(yè)第190頁(yè)第191頁(yè)第192頁(yè)第193頁(yè)第194頁(yè)第195頁(yè)第196頁(yè)第197頁(yè)第198頁(yè)第199頁(yè)第200頁(yè)第201頁(yè)第202頁(yè)第203頁(yè)第204頁(yè)第205頁(yè)第206頁(yè)第207頁(yè)第208頁(yè)第209頁(yè)第210頁(yè)第211頁(yè)第212頁(yè)第213頁(yè)第214頁(yè)第215頁(yè)第216頁(yè)第217頁(yè)第218頁(yè)第219頁(yè)第220頁(yè)第221頁(yè)第222頁(yè)第223頁(yè)第224頁(yè)第225頁(yè)第226頁(yè)第227頁(yè)第228頁(yè)第229頁(yè)第230頁(yè)第231頁(yè)第232頁(yè)第233頁(yè)第234頁(yè)第235頁(yè)第236頁(yè)第237頁(yè)第238頁(yè)第239頁(yè)第240頁(yè)第241頁(yè)第242頁(yè)第243頁(yè)第244頁(yè)第245頁(yè)第246頁(yè)第247頁(yè)第248頁(yè)第249頁(yè)第250頁(yè)第251頁(yè)第252頁(yè)第253頁(yè)第254頁(yè)第255頁(yè)第256頁(yè)
56
Am79C978A
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
Initialization includes the reading of the initialization
block in memory to obtain the operating 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 Am79C978A controller always per-
forms 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
before or concurrent with the STRT bit to insure cor-
rect operation. Once the initialization block has been
completely read in and internal registers have been
updated, IDON will be set in CSR0, generating an in-
terrupt (if IENA is set).
TheAm79C978A controller obtains the start address of
the initialization block from the contents of CSR1 (least
significant 16 bits of address) and CSR2 (most signifi-
cant 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 operation, to-
gether with the base addresses and length information
of the transmit and receive descriptor rings.
There is an alternate method to initialize the
Am79C978A controller. Instead of initialization via
the initialization block in memory, data can be writ-
ten directly into the appropriate registers. Either
method or a combination of the two may be used
at the discretion of the programmer. Refer to
Ap-
pendix A, Alternative Method for Initialization
for
details on this alternate method.
Re-Initialization
The transmitter and receiver sections of the
Am79C978A controller can be turned on via the initial-
ization block (DTX, DRX, CSR15, bits 1-0). The states
of the transmitter and receiver are monitored by the
host through CSR0 (RXON, TXON bits).
TheAm79C978A controller should be re-initialized 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 section was shut
off due to the detection of an error condition (MERR,
UFLO, TX BUFF error).
Re-initialization may be done via the initialization block
or by setting the STOP bit in CSR0, followed by writing
to CSR15, and then setting the START bit in CSR0.
Note that this form of restart will not perform the same
in the Am79C978A controller as in the C-LANCE de-
vice. In particular, upon restart, the Am79C978A con-
troller reloads the transmit and receive descriptor
pointers with their respective base addresses. This
means that the software must clear the descriptor
OWN bits and reset its descriptor ring pointers before
restarting the Am79C978A controller. The reload of de-
scriptor base addresses is performed in the C-LANCE
device only after initialization, so that a restart of the C-
LANCE without initialization leaves the C-LANCE
pointing at the same descriptor locations as before the
restart.
Suspend
TheAm79C978A controller offers two suspend modes
that allow easy updating of the CSR registers without
going through a full re-initialization of the device. The
suspend modes also allow stopping the device with
orderly termination of all network activity.
The host requests the Am79C978A controller to enter
the suspend mode by setting SPND (CSR5, bit 0) to
1. The host must poll SPND until it reads back 1 to de-
termine that the Am79C978A controller has entered
the suspend mode. When the host sets SPND to 1,
the procedure taken by the Am79C978A controller to
enter the suspend mode depends on the setting of the
fast suspend enable bit (FASTSPND, CSR7, bit 15).
When a fast suspend is requested (FASTSPND is
set to 1), the Am79C978A controller performs a
quick entry into the suspend mode. At the time the
SPND bit is set, the Am79C978A controller will con-
tinue the DMA process of any transmit and/or re-
ceive packets that have already begun DMA activity
until the network activity has been completed. In ad-
dition, any transmit packet that had started transmis-
sion will be fully transmitted and any receive packet
that had begun reception will be fully received. How-
ever, no additional packets will be transmitted or re-
ceived and no additional transmit or receive DMA
activity will begin after network activity has ceased.
Hence, the Am79C978A controller may enter the
suspend mode with transmit and/or receive packets
still in the FIFOs or the SRAM. This offers a worst
case suspend time of a maximum length packet over
the possibility of completely emptying the SRAM.
Care must be exercised in this mode, because the
entire memory subsystem of the Am79C978A con-
troller is suspended. Any changes to either the de-
scriptor rings or the SRAM can cause the
Am79C978A controller to start up in an unknown
condition and could cause data corruption.
相關(guān)PDF資料
PDF描述
AM79C978AVCW Single-Chip 1/10 Mbps PCI Home Networking Controller
AM79C978 Single-Chip 1/10 Mbps PCI Home Networking Controller
AM79C981 Integrated Multiport Repeater Plus⑩ (IMR+⑩)
AM79C981JC Integrated Multiport Repeater Plus⑩ (IMR+⑩)
AM79C982 basic Integrated Multiport Repeater (bIMR)
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AM79C978AVCW 制造商:AMD 制造商全稱:Advanced Micro Devices 功能描述:Single-Chip 1/10 Mbps PCI Home Networking Controller
AM79C978KC/W 制造商:AMD 制造商全稱:Advanced Micro Devices 功能描述:Single-Chip 1/10 Mbps PCI Home Networking Controller
AM79C978VC/W 制造商:AMD 制造商全稱:Advanced Micro Devices 功能描述:Single-Chip 1/10 Mbps PCI Home Networking Controller
AM79C979BKC\\W 制造商:Advanced Micro Devices 功能描述:
AM79C98 制造商:AMD 制造商全稱:Advanced Micro Devices 功能描述:Twisted-Pair Ethernet Transceiver (TPEX)