參數(shù)資料
型號(hào): AM79C974
廠商: Advanced Micro Devices, Inc.
英文描述: PCnetTM-SCSI Combination Ethernet and SCSI Controller for PCI Systems
中文描述: PCnetTM -的SCSI結(jié)合以太網(wǎng)和SCSI控制器PCI系統(tǒng)
文件頁(yè)數(shù): 22/153頁(yè)
文件大?。?/td> 838K
代理商: AM79C974
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)當(dāng)前第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)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)
AMD
P R E L I M I N A R Y
22
Am79C974
LED3
LED3
Output
This pin is shared with the EEDO function of the
Microwire serial EEPROM interface. When functioning
as
LED3
, the signal on this pin is programmable through
BCR7. By default,
LED3
is active LOW and it indicates
transmit activity on the network. Special attention must
be given to the external circuitry attached to this pin. If
an LED circuit were directly attached to this pin, it would
create an I
OL
requirement that could not be met by the
serial EEPROM that would also be attached to this pin.
Therefore, if this pin is to be used as an additional LED
output while an EEPROM is used in the system, then
buffering is required between the
LED3
pin and the LED
circuit. If no EEPROM is included in the system design,
then the
LED3
signal may be directly connected to an
LED without buffering. The
LED3
output from the
PCnet-SCSI controller is capable of sinking the 12 mA of
current necessary to drive an LED in this case. For more
details regarding LED connection, see the section on
LEDs.
LNKST
LINK Status
Output
This pin provides 12 mA for driving an LED. By default, it
indicates an active link connection on the 10BASE-T in-
terface. This pin can also be programmed to indicate
other network status (see BCR4). The
LNKST
pin
polarity is programmable, but by default, it is active
LOW. Note that this pin is multiplexed with the EEDI
function.
SLEEP
Sleep
Input
When
SLEEP
is asserted (active LOW), the PCnet-
SCSI controller performs an internal system reset of the
S_RESET type and then proceeds into a power savings
mode. (The reset operation caused by
SLEEP
assertion
will not affect BCR registers.) The PCI interface section
is not effected by
SLEEP
. In particular, access to the
PCI configuration space remains possible. None of the
configuration registers will be reset by
SLEEP
. All I/O
accesses to the PCnet-SCSI controller will result in a
PCI target abort response. The PCnet-SCSI controller
will not assert
REQ
while in sleep mode. When
SLEEP
is asserted, all non-PCI interface outputs will be placed
in their normal S_RESET condition. All non-PCI inter-
face inputs will be ignored except for the
SLEEP
pin it-
self. De-assertion of
SLEEP
results in wake-up. The
system must refrain from starting the network opera-
tions of the PCnet-SCSI device for 0.5 seconds follow-
ing the deassertion of the
SLEEP
signal in order to allow
internal analog circuits to stabilize.
Both CLK and XTAL1 inputs must have valid clock sig-
nals present in order for the
SLEEP
command to take
effect. If
SLEEP
is asserted while
REQ
is asserted, then
the PCnet-SCSI controller will wait for the assertion of
GNT
. When
GNT
is asserted, the
REQ
signal will be de-
asserted and then the PCnet-SCSI controller will pro-
ceed to the power savings mode.
The
SLEEP
pin should not be asserted during power
supply ramp-up. If it is desired that
SLEEP
be asserted
at power up time, then the system must delay the asser-
tion of
SLEEP
until three CLK cycles after the comple-
tion of a valid pin
RST
operation.
The
SLEEP
pin does not affect the SCSI section.
XTAL1
Crystal Oscillator Input
Input
XTAL2
Crystal Oscillator Output
Output
The crystal frequency determines the network data rate.
The PCnet-SCSI controller supports the use of quartz
crystals to generate a 20 MHz frequency compatible
with the ISO 8802-3 (IEEE/ANSI 802.3) network fre-
quency tolerance and jitter specifications. See the sec-
tion External Crystal Characteristics (in section
Manchester Encoder/Decoder) for more detail.
The network data rate is one-half of the crystal fre-
quency. XTAL1 may alternatively be driven using an ex-
ternal CMOS level source, in which case XTAL2 must
be left unconnected. Note that when the PCnet-SCSI
controller is in coma mode, there is an internal 22 K
re-
sistor from XTAL1 to ground. If an external source drives
XTAL1, some power will be consumed driving this resis-
tor. If XTAL1 is driven LOW at this time power consump-
tion will be minimized. In this case, XTAL1 must remain
active for at least 30 cycles after the assertion of
SLEEP
and deassertion of
REQ
.
Microwire EEPROM Interface
EESK
EEPROM Serial Clock
Input/Output
The EESK signal is used to access the external ISO
8802-3 (IEEE/ANSI 802.3) address PROM. This pin is
designed to directly interface to a serial EEPROM that
uses the Microwire interface protocol. EESK is con-
nected to the Microwire EEPROM’s Clock pin. It is con-
trolled by either the PCnet-SCSI controller directly
during a read of the entire EEPROM, or indirectly by the
host system by writing to BCR19, bit 1.
The EESK pin is also used during EEPROM Auto-detec-
tion to determine whether or not an EEPROM is present
相關(guān)PDF資料
PDF描述
AM79C974KCW PCnetTM-SCSI Combination Ethernet and SCSI Controller for PCI Systems
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
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
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
AM79C974KCW 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
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