參數(shù)資料
型號: AM79C970A
廠商: Advanced Micro Devices, Inc.
英文描述: PCnet-PCI II Single-Chip Full-Duplex Ethernet Controller for PCI Local Bus Product
中文描述: PCnet - 2的PCI單芯片全雙工以太網(wǎng)控制器,適用于PCI總線產(chǎn)品
文件頁數(shù): 88/219頁
文件大小: 1065K
代理商: AM79C970A
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頁當(dāng)前第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
AMD
P R E L I M I N A R Y
88
Am79C970A
Full-Duplex Operation
The PCnet-PCI II controller supports full-duplex opera-
tion on all three network interfaces: AUI, 10BASE-T, and
GPSI. full-duplex operation allows simultaneous trans-
mit and receive activity on the TXD
±
and RXD
±
pairs of
the 10BASE-T port, the DO
±
and DI
±
pairs of the AUI
port, or the TXDAT and RXDAT pins of the GPSI port.
Full-duplex operation is enabled by the FDEN and
AUIFD bits located in BCR9. When operating in full-du-
plex mode, the following changes to the device opera-
tion are made:
Bus Interface/Buffer Management Unit changes:
I
The first 64 bytes of every transmit frame are not pre-
served in the transmit FIFO during transmission of
the first 512 bits as described in the section “Trans-
mit Exception Conditions”. Instead, when full-duplex
mode is active and a frame is being transmitted, the
XMTFW bits (CSR80, bits 9–8) always
govern when
transmit DMA is requested.
I
Successful reception of the first 64 bytes of every re-
ceive frame is not a requirement for receive DMA to
begin as described in the section “Receive Excep-
tion Condition”. Instead, receive DMA will be re-
quested as soon as either the Receive FIFO
Watermark (CSR80, bits 13–12) is reached or a
complete valid receive frame is detected, regardless
of length. This receive FIFO operation is identical to
when the RPA bit (CSR124, bit 3) is set during half-
duplex mode operation.
MAC Engine changes:
I
Changes to the Transmit Deferral mechanism:
– Transmission is not deferred while receive is
active.
– The Inter Packet Gap (IPG) counter which gov-
erns transmit deferral during the IPG between
back-to-back transmits is started when transmit
activity for the first packet ends instead of when
transmit and carrier activity ends.
I
When the AUI or GPSI port is active, Loss of Carrier
(LCAR) reporting is disabled. (LCAR is still reported
when the 10BASE-T port is active if a packet is trans-
mitted while in Link Fail state.)
I
The 4.0
μ
s carrier sense blinding period after a trans-
mission during which the SQE test normally occurs is
disabled.
I
When the AUI or GPSI port is active, the SQE Test
error reporting (CERR) is disabled. (CERR is still re-
ported when the 10BASE-T port is active if a packet
is transmitted while in Link Fail state.)
I
The collision indication input to the MAC engine is
ignored.
T-MAU changes:
I
The internal transmit to receive feedback path which
is used to indicate carrier sense during normal trans-
mission in half-duplex mode is disabled.
I
The collision detect circuit is disabled.
I
The SQE test function is disabled.
Full-Duplex Link Status LED Support
The PCnet-PCI II controller provides a bit in each of the
LED Status registers (BCR4, BCR5, BCR6, BCR7) to
display the Full-Duplex Link Status. If the FDLSE bit
(bit 8) is set, a value of ONE will be sent to the associ-
ated LEDOUT bit when the T-MAU is in the Full-Duplex
Link Pass state.
General Purpose Serial Interface
The General Purpose Serial Interface (GPSI) provides a
direct interface to the MAC section of the PCnet-PCI II
controller. All signals are digital and data is non-en-
coded. The GPSI allows use of an external Manchester
encoder/decoder such as the Am7992B Serial Interface
Adapter (SIA). In addition, it allows the PCnet-PCI II
controller to be used as a MAC sublayer engine in a re-
peater designs based on the Am79C981 IMR+.
GPSI mode is invoked by setting the GPSIEN bit
(CSR124, bit 4) to ONE and by selecting the interface
through the PORTSEL bits of the Mode register
(CSR15, bits 8–7).
The GPSI interface uses some of the same pins as the
interface to the Expansion ROM. Simultaneous use of
both functions is not possible. Reading from the Expan-
sion ROM and then reconfiguring the pins to the GPSI
mode is supported. With this approach an external
transceiver is required to prevent contention between
the GPSI signals and the data outputs from the Expan-
sion ROM.
EROE
can be used as control signal for the
external transceiver.
After an H_RESET all pins are internally configured to
function as Expansion ROM interface. When the GPSI
interface is selected by setting PORTSEL (CSR15, bits
8–7) to 10b, the PCnet-PCI II controller will terminate all
further read accesses to Expansion ROM by asserting
TRDY
within two clock cycles. The read data will
be undefined.
During the boot procedure the system will try to find an
Expansion ROM. A PCI system assumes that an Expan-
sion ROM is present when it reads the ROM signature
55h (byte 0) and AAh (byte 1). A design without Expan-
sion ROM can guarantee that the Expansion ROM de-
tection fails by connecting two adjacent ERD pins
together. The recommended pins are pin 77
(ERD6/TXEN) and pin 78 (ERD5), since TXEN should
have an external pull-down.
GPSI signal functions are described in the pin descrip-
tion section under the GPSI subheading.
相關(guān)PDF資料
PDF描述
AM79C970AVCW PCnet-PCI II Single-Chip Full-Duplex Ethernet Controller for PCI Local Bus Product
AM79C970 PCnetTM-PCI Single-Chip Ethernet Controller for PCI Local Bus
AM79C971VCW PCnet⑩-FAST Single-Chip Full-Duplex 10/100 Mbps Ethernet Controller for PCI Local Bus
AM79C971 PCnet⑩-FAST Single-Chip Full-Duplex 10/100 Mbps Ethernet Controller for PCI Local Bus
AM79C971KCW IC LOGIC 16211 24-BIT FET BUS SWITCH -40+85C TSSOP-56 35/TUBE
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AM79C970AKC 制造商:AMD 制造商全稱:Advanced Micro Devices 功能描述:PCnet-PCI II Single-Chip Full-Duplex Ethernet Controller for PCI Local Bus Product
AM79C970AKC\\W 制造商:Rochester Electronics LLC 功能描述:- Bulk 制造商:Advanced Micro Devices 功能描述:
AM79C970AKC\W 制造商:Rochester Electronics LLC 功能描述:- Bulk
AM79C970AKCW 制造商:AMD 制造商全稱:Advanced Micro Devices 功能描述:PCnet-PCI II Single-Chip Full-Duplex Ethernet Controller for PCI Local Bus Product