參數(shù)資料
型號: AM79C961AKIW
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, PQFP132
封裝: PLASTIC, QFP-132
文件頁數(shù): 88/206頁
文件大?。?/td> 1507K
代理商: AM79C961AKIW
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
88
Am79C961A
ISA Configuration Register Cycles
The ISA configuration register is accessed by placing
the address of the desired register into the RAP and
reading the IDP. The ISACSR bus cycles are identical
to all other PCnet-ISA II controller register bus cycles.
Boot PROM Cycles
The Boot PROM is an 8-bit PROM connected to the
PCnet-ISA II controller Private Data Bus (PRDB), and
can occupy up to 64 Kbytes of address space. In
Shared Memory Mode, an external address compara-
tor is responsible for asserting BPAM to the PCnet-ISA
II controller. BPAM is intended to be a perfect decode
of the boot PROM address space, i.e. LA17-23, SA16.
The LA bus must be latched with BALE in order to pro-
vide stable signal for BPAM. REF inactive must be
used by the external logic to gate boot PROM address
decoding. This same logic must assert MEMCS16 to
the ISA bus if 16-bit Boot PROM bus cycles are
desired.
In the Bus Slave mode, boot PROM cycles can be pro-
grammed to be 8 or 16-bit ISA memory cycles with the
BP_16B bit (PnP 0x42). If the BP_16B bit is set, the
PCnet-ISA II assumes 16-bit ISA memory cycles for
the boot PROM. In this case, the external hardware
responsible for generating BPAM must also generate
MEMCS16. A 16-bit boot PROM bus cycle begins with
the Permanent Master driving the addresses valid and
MEMR active. (AEN is not involved in memory cycles).
External hardware would assert BPAM and MEMCS16.
The PCnet-ISA II controller detects this combination of
signals, drives IOCHRDY LOW, and reads two bytes
out of the boot PROM. The data bytes read from the
PROM are driven by the PCnet-ISA II controller onto
SD0-15 and IOCHRDY is released. This condition is
maintained until MEMR goes inactive, at which time the
access cycle ends.
The PCnet-ISA II controller will perform 8-bit ISA bus
cycle operation for all resource (registers, PROMs,
SRAM) if SBHE has been left unconnected, such as in
the case of an 8-bit system like the PC/XT.
The BPCS signal generated by the PCnet-ISA II con-
troller is three 20 MHz clock cycles wide (350 ns).
Including delays, the Boot PROM has 275 ns to
respond to the BPCS signal from the PCnet-ISA II con-
troller. This signal is intended to be connected to the
CS pin on the boot PROM, with the PROM OE pin tied
to ground.
Static RAM Cycles
Shared Memory Architecture
In the Shared Memory Architecture mode, the SRAM is
an 8-bit device connected to the PCnet-ISA II controller
Private Bus, and can occupy up to 64 Kbytes of
address space. The SRAM is memory mapped into the
ISA memory space at an address range determined by
external decode logic. The external address compara-
tor is responsible for asserting SMAM to the PCnet-ISA
II controller. SMAM is intended to be a perfect decode
of the SRAM address space, i.e. LA17-23, SA16 for 64
Kbytes of SRAM. The LA signals must be latched by
BALE in order to provide a stable decode for SMAM.
The PCnet-ISA II controller assumes 16-bit ISA mem-
ory bus cycles for the SRAM, so this same logic must
assert MEMCS16 to the ISA bus if 16-bit bus cycles are
to be supported.
A 16-bit SRAM bus cycle begins with the Permanent
Master driving the addresses valid, REF inactive, and
either MEMR or MEMW active. (AEN is not involved in
memory cycles). External hardware would assert
SMAM and MEMCS16. The PCnet-ISA II controller
detects this combination of signals and initiates the
SRAM access.
In a write cycle, the PCnet-ISA II controller stores the
data into an internal holding register, allowing the ISA
bus cycle to finish normally. The data in the holding reg-
ister will then be written to the SRAM without the need
for ISA bus control. In the event the holding register is
already filled with unwritten SRAM data, the PCnet-ISA
II controller will extend the ISA write cycle by driving
IOCHRDY LOW until the unwritten data is stored in the
SRAM. The current ISA bus cycle will then complete
normally.
In a read cycle, the PCnet-ISA II controller arbitrates for
the Private Bus. If it is unavailable, the PCnet-ISA II
controller drives IOCHRDY LOW. The PCnet-ISA II
controller compares the 16 bits of address on the Sys-
tem Address Bus with that of a data word held in an
internal pre-fetch register.
If the address does not match that of the prefetched
SRAM data, then the PCnet-ISA II controller drives
IOCHRDY LOW and reads two bytes from the SRAM.
The PCnet-ISA II controller then proceeds as though
the addressed data location had been prefetched.
If the internal prefetch buffer contains the correct data,
then the pre-fetch buffer data is driven on the System
Data bus. If IOCHRDY was previously driven LOW due
to either Private Data Bus arbitration or SRAM access,
then it is released HIGH. The PCnet-ISA II controller
remains in this state until MEMR is de-asserted, at
which time the PCnet-ISA II controller performs a new
prefetch of the SRAM. In this way memory read wait
states can be minimized.
The PCnet-ISA II controller performs prefetches of the
SRAM between ISA bus cycles. The SRAM is
prefetched in an incrementing word address fashion.
Prefetched data are invalidated by any other activity on
the Private Bus, including Shared Memory Writes by
either the ISA bus or the network interface, and also
address and boot PROM reads.
相關(guān)PDF資料
PDF描述
AM79C961AVCW PCnet⑩-ISA II Jumperless, Full Duplex Single-Chip Ethernet Controller for ISA
AM79C961AVIW PCnet⑩-ISA II Jumperless, Full Duplex Single-Chip Ethernet Controller for ISA
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
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AM79C961APDLUTS 制造商:Advanced Micro Devices 功能描述:
AM79C961AVC 制造商:Rochester Electronics LLC 功能描述: 制造商:Advanced Micro Devices 功能描述:LAN Node Controller, 144 Pin, TQFP
AM79C961AVC/W 制造商:未知廠家 制造商全稱:未知廠家 功能描述:LAN Node Controller
AM79C961AVC\\W 制造商:Rochester Electronics LLC 功能描述:
AM79C961AVC\W 制造商:Rochester Electronics LLC 功能描述: