參數(shù)資料
型號(hào): AM79C961AVIW
廠商: ADVANCED MICRO DEVICES INC
元件分類: 微控制器/微處理器
英文描述: PCnet⑩-ISA II Jumperless, Full Duplex Single-Chip Ethernet Controller for ISA
中文描述: 2 CHANNEL(S), 10M bps, LOCAL AREA NETWORK CONTROLLER, PQFP144
封裝: TQFP-144
文件頁(yè)數(shù): 87/206頁(yè)
文件大?。?/td> 1507K
代理商: AM79C961AVIW
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)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)當(dāng)前第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)
Am79C961A
87
lower priority DRQ pin than the one currently being
used by the PCnet-ISA II is asserted, the PCnet-ISA II
will wait 2.6
μ
s after the deassertion of DACK before
re-asserting its DRQ pin. If no lower priority DRQ pin is
asserted, the PCnet-ISA II may re-assert its DRQ pin
after as short as 1.1
μ
s following DACK deassertion.
The priorities assumed by the PCnet-ISA II are ordered
DRQ3, DRQ5, DRQ6, DRQ7, with DRQ3 having high-
est priority and DRQ7 having the lowest priority. This
priority ordering matches that used by typical ISA bus
DMA controllers.
This adaptive delay scheme allows for fair bus band-
width sharing when two bus mastering devices, e.g.
two PCnet-ISA II devices, are on an ISA bus. The con-
troller using the higher priority DMA channel cannot
lock out the controller using the lower priority DMA
channel because of the 2.6
μ
s delay that is inserted
before DRQ reassertion when a lower priority DRQ pin
is asserted. When there is no lower priority DMA
request asserted, the PCnet-ISA II re-requests the bus
immediately, providing optimal performance when
there is no competition for bus access.
Bus Slave Mode
The PCnet-ISA II can be configured to be a bus slave
for systems that do not support bus mastering or
require a local memory to tolerate high bus latencies.
In the Bus Slave mode, the I/O map of the PCnet-ISA
II is identical to the I/O map when in the Bus Master
mode (see I/O Resources section). Hence, the address
PROM, controller registers, and Reset port are
accessed through I/O cycles on the ISA bus. However,
the initialization block, descriptor rings, and buffers,
which are located in system memory when in the Bus
Master mode, are located in a local SRAM when in the
Bus Slave mode. The local SRAM can be accessed by
memory cycles on the ISA bus (Shared Memory archi-
tecture) or by I/O cycles on the ISA bus (Programmed
I/O mode).
Address PROM Cycles External PROM
The Address PROM is a small (16 bytes) 8-bit PROM
connected to the PCnet-ISA II controller Private Data
Bus (PRDB). The PCnet-ISA II controller will support
only 8-bit ISA I/O bus cycles for the address PROM;
this limitation is transparent to software and does not
preclude 16-bit software I/O accesses. An access cycle
begins with the Permanent Master driving AEN LOW,
driving the addresses valid, and driving IOR active. The
PCnet-ISA II controller detects this combination of sig-
nals and arbitrates for the Private Data Bus if neces-
sary. IOCHRDY is always driven LOW during address
PROM accesses.
When the Private Data Bus becomes available, the
PCnet-ISA II controller drives APCS active, releases
IOCHRDY, turns on the data path from PRD0-7, and
enables the SD0-7 drivers (but not SD8-15). During
this bus cycle, IOCS16 is not driven active. This condi-
tion is maintained until IOR goes inactive, at which time
the access cycle ends. Data is removed from SD0-7
within 30 ns.
The PCnet-ISA II controller will perform 8-bit ISA bus
cycle operation for all resources (registers, PROMs,
SRAM) if SBHE has been left unconnected, such as in
the case of an 8-bit system like the PC/XT.
Ethernet Controller Register Cycles
Ethernet controller registers (RAP, RDP, ISACSR) are
naturally 16-bit resources but can be configured to
operate with 8-bit bus cycles provided the proper pro-
tocol is followed. This is programmable by the
EEPROM. This means on a read, the PCnet-ISA II con-
troller will only drive the low byte of the system data
bus; if an odd byte is accessed, it will be swapped
down. The high byte of the system data bus is never
driven by the PCnet-ISA II controller under these con-
ditions. On a write, the even byte is placed in a holding
register. An odd-byte write is internally swapped up and
augmented with the even byte in the holding register to
provide an internal 16-bit write. This allows the use of
8-bit I/O bus cycles which are more likely to be compat-
ible with all clones, but requires that both bytes be writ-
ten in immediate succession. This is accomplished
simply by treating the PCnet-ISA II controller controller
registers as 16-bit software resources. The mother-
board will convert the 16-bit accesses done by soft-
ware into two sequential 8-bit accesses, an even-byte
access followed immediately by an odd-byte access.
An access cycle begins with the Permanent Master
driving AEN LOW, driving the address valid, and driv-
ing IOR or IOW active. The PCnet-ISA II controller de-
tects this combination of signals and drives IOCHRDY
LOW. IOCS16 will also be driven LOW if 16-bit I/O bus
cycles are enabled. When the register data is ready,
IOCHRDY will be released HIGH. This condition is
maintained until IOR or IOW goes inactive, at which
time the bus cycle ends.
The PCnet-ISA II controller will perform 8-bit ISA bus
cycle operation for all resources (registers, PROMs,
SRAM) if SBHE has been left unconnected, such as in
the case of an 8-bit system like the PC/XT.
RESET Cycles
A read to the reset address causes an PCnet-ISA II
controller reset. This has the same effect as asserting
the RESET pin on the PCnet-ISA
+
controller (which
happens on system power up or on a hard boot) except
that the T-MAU is NOT reset. The T-MAU will retain its
link pass/fail state, disregarding the software RESET
command. The subsequent write cycle needed in the
NE2100 LANCE- based family of Ethernet cards is not
required but does not have any harmful effects.
IOCS16 is not asserted in this cycle.
相關(guān)PDF資料
PDF描述
Am79C965A PCnet?-32 Single-Chip 32-Bit Ethernet Controller
AM79C970AKCW PCnet-PCI II Single-Chip Full-Duplex Ethernet Controller for PCI Local Bus Product
AM79C970AKC PCnet-PCI II Single-Chip Full-Duplex Ethernet Controller for PCI Local Bus Product
AM79C970A PCnet-PCI II Single-Chip Full-Duplex Ethernet Controller for PCI Local Bus Product
AM79C970AVCW PCnet-PCI II Single-Chip Full-Duplex Ethernet Controller for PCI Local Bus Product
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AM79C961AWW WAF 制造商:Advanced Micro Devices 功能描述:
AM79C961KC 制造商:AMD 制造商全稱:Advanced Micro Devices 功能描述:PCnetTM-ISA+ Jumperless Single-Chip Ethernet Controller for ISA
AM79C961KC/W 制造商:AMD 制造商全稱:Advanced Micro Devices 功能描述:PCnetTM-ISA+ Jumperless Single-Chip Ethernet Controller for ISA
AM79C965A 制造商:AMD 制造商全稱:Advanced Micro Devices 功能描述:PCnet?-32 Single-Chip 32-Bit Ethernet Controller