AMD Lance Am7990
Encyclopedia
AMD Lance Am7990 IEEE 802.3
Ethernet Media Access Control
ler (MAC) controller were introduced in 1985. Its architecture is the basis for AMD
’s PCnet Family of highly integrated single-chip Ethernet controllers. The one exception is the Am79C940 MAC.
The Am7990 chip was fabricated in NMOS
technology and has no integrated Manchester
encoder/decoder (ENDEC) nor does it have an integrated 10BASE-T
transceiver.
technology. The original NMOS version Am7990 and the CMOS Am79C90 version are differ in some details which may have an impact on device driver
compatibility.
The datasheet for the CMOS version writes that the CMOS and NMOS versions are the same. But the "Table B-1. Comparison Summary of the C-LANCE and LANCE Devices" in the datasheet
shows they differ. These differences are not likely to require modifications of any device driver.
The PCnet family of Ethernet controllers (PCnet-ISA
II, PCnet-32, PCnet-PCI II and PCnet-FAST) is LANCE software compatible. This means you should be able use the original 16-bit software on these members of the PCnet family of single-chip Ethernet controllers.
/Bus mastering
24-bit (16M) address capable. Up to 128 ring buffers can be used. 48 byte receive/transmit FIFO. Operates with supply and logic. Features an Time-domain reflectometer
(TDR) with an granularity of 30 meter. maximum frequency.
Physically a DIP-48
or PLCC-68
package is used.
CSR0 slave read data can cause timing violations on DAL lines.
support.
The Amiga
SANA-II network interface API has poor multicast support. And this chip bug might be the reason.
No capability for transmit buffer byte count of zero.
Receive lockup may occur if bus latency is large.
External loopback on a live network may cause reception of invalid loopback failure indications.
Receive descriptor zero byte count buffer interpreted as 4096 available bytes.
Will poll
computer memory every 1.6 ms
for new packets to transmit.
IEEE 802.3
IEEE 802.3 is a working group and a collection of IEEE standards produced by the working group defining the physical layer and data link layer's media access control of wired Ethernet. This is generally a local area network technology with some wide area network applications...
Ethernet Media Access Control
Media Access Control
The media access control data communication protocol sub-layer, also known as the medium access control, is a sublayer of the data link layer specified in the seven-layer OSI model , and in the four-layer TCP/IP model...
ler (MAC) controller were introduced in 1985. Its architecture is the basis for AMD
Advanced Micro Devices
Advanced Micro Devices, Inc. or AMD is an American multinational semiconductor company based in Sunnyvale, California, that develops computer processors and related technologies for commercial and consumer markets...
’s PCnet Family of highly integrated single-chip Ethernet controllers. The one exception is the Am79C940 MAC.
The Am7990 chip was fabricated in NMOS
NMOS logic
N-type metal-oxide-semiconductor logic uses n-type metal-oxide-semiconductor field effect transistors to implement logic gates and other digital circuits...
technology and has no integrated Manchester
Manchester code
In telecommunication and data storage, Manchester code is a line code in which the encoding of each data bit has at least one transition and occupies the same time...
encoder/decoder (ENDEC) nor does it have an integrated 10BASE-T
10BASE-T
Ethernet over twisted pair technologies use twisted-pair cables for the physical layer of an Ethernet computer network. Other Ethernet cable standards employ coaxial cable or optical fiber. Early versions developed in the 1980s included StarLAN followed by 10BASE-T. By the 1990s, fast, inexpensive...
transceiver.
Compatibility
A later refabricated chip called the C-LANCE Am79C90 is made with 0.8 micrometre CMOSCMOS
Complementary metal–oxide–semiconductor is a technology for constructing integrated circuits. CMOS technology is used in microprocessors, microcontrollers, static RAM, and other digital logic circuits...
technology. The original NMOS version Am7990 and the CMOS Am79C90 version are differ in some details which may have an impact on device driver
Device driver
In computing, a device driver or software driver is a computer program allowing higher-level computer programs to interact with a hardware device....
compatibility.
The datasheet for the CMOS version writes that the CMOS and NMOS versions are the same. But the "Table B-1. Comparison Summary of the C-LANCE and LANCE Devices" in the datasheet
Datasheet
thumb|A floppy disk controller datasheet.A datasheet, data sheet, or spec sheet is a document summarizing the performance and other technical characteristics of a product, machine, component , material, a subsystem or software in sufficient detail to be used by a design engineer to integrate the...
shows they differ. These differences are not likely to require modifications of any device driver.
The PCnet family of Ethernet controllers (PCnet-ISA
Industry Standard Architecture
Industry Standard Architecture is a computer bus standard for IBM PC compatible computers introduced with the IBM Personal Computer to support its Intel 8088 microprocessor's 8-bit external data bus and extended to 16 bits for the IBM Personal Computer/AT's Intel 80286 processor...
II, PCnet-32, PCnet-PCI II and PCnet-FAST) is LANCE software compatible. This means you should be able use the original 16-bit software on these members of the PCnet family of single-chip Ethernet controllers.
Features
The Am7990 can handle 10BASE-5 Type A, 10BASE-2 Type B, and 10BASE-T. Back-to-back packet reception with as little as 0,5 µs interframe spacing. DMADirect memory access
Direct memory access is a feature of modern computers that allows certain hardware subsystems within the computer to access system memory independently of the central processing unit ....
/Bus mastering
Bus mastering
In computing, bus mastering is a feature supported by many bus architectures that enables a device connected to the bus to initiate transactions...
24-bit (16M) address capable. Up to 128 ring buffers can be used. 48 byte receive/transmit FIFO. Operates with supply and logic. Features an Time-domain reflectometer
Time-domain reflectometer
A time-domain reflectometer is an electronic instrument used to characterize and locate faults in metallic cables . It can also be used to locate discontinuities in a connector, printed circuit board, or any other electrical path...
(TDR) with an granularity of 30 meter. maximum frequency.
Physically a DIP-48
Dual in-line package
In microelectronics, a dual in-line package is an electronic device package with a rectangular housing and two parallel rows of electrical connecting pins. The package may be through-hole mounted to a printed circuit board or inserted in a socket.A DIP is usually referred to as a DIPn, where n is...
or PLCC-68
Plastic leaded chip carrier
A plastic leaded chip carrier is a chip carrier with a equiangular plastic housing. It is a reduced cost evolution of the ceramic leadless chip carrier ....
package is used.
CSR0 slave read data can cause timing violations on DAL lines.
Chip bugs
The old LANCE (Rev. C) chips have a bug which causes garbage to be inserted in front of the received packet. The workaround is to ignore packets with an invalid destination address (garbage will usually not match). Of course, this precludes multicastMulticast
In computer networking, multicast is the delivery of a message or information to a group of destination computers simultaneously in a single transmission from the source creating copies automatically in other network elements, such as routers, only when the topology of the network requires...
support.
The Amiga
Amiga
The Amiga is a family of personal computers that was sold by Commodore in the 1980s and 1990s. The first model was launched in 1985 as a high-end home computer and became popular for its graphical, audio and multi-tasking abilities...
SANA-II network interface API has poor multicast support. And this chip bug might be the reason.
No capability for transmit buffer byte count of zero.
Receive lockup may occur if bus latency is large.
External loopback on a live network may cause reception of invalid loopback failure indications.
Receive descriptor zero byte count buffer interpreted as 4096 available bytes.
Will poll
Polling (computer science)
Polling, or polled operation, in computer science, refers to actively sampling the status of an external device by a client program as a synchronous activity. Polling is most often used in terms of input/output , and is also referred to as polled or software driven .Polling is sometimes used...
computer memory every 1.6 ms
Millisecond
A millisecond is a thousandth of a second.10 milliseconds are called a centisecond....
for new packets to transmit.
Uses
- Amiga 2065 the first Ethernet controller for Amiga computer family. Uses the Zorro-II bus interface and equipped with the NMOS Am7990 chip.
- MicroVAXMicroVAXThe MicroVAX was a family of low-end minicomputers developed and manufactured by Digital Equipment Corporation . The first model, the MicroVAX I, was introduced in 1984...
Q-BusQ-BusThe Q-bus was one of several bus technologies used with PDP and MicroVAX computer systems manufactured by the Digital Equipment Corporation of Maynard, Massachusetts....
Ethernet controllers (like the DELQA).
- DECstation 2100/3100 MIPS architectureMIPS architectureMIPS is a reduced instruction set computer instruction set architecture developed by MIPS Technologies . The early MIPS architectures were 32-bit, and later versions were 64-bit...
motherboardMotherboardIn personal computers, a motherboard is the central printed circuit board in many modern computers and holds many of the crucial components of the system, providing connectors for other peripherals. The motherboard is sometimes alternatively known as the mainboard, system board, or, on Apple...
Ethernet.
- DEC 3000 AXPDEC 3000 AXPDEC 3000 AXP was the name given to a series of computer workstations and servers, produced from 1992 to around 1995 by Digital Equipment Corporation. The DEC 3000 AXP series formed part of the first generation of computer systems based on the 64-bit Alpha AXP architecture...
64-bit Alpha AXP architecture motherboard.
- Sun MicrosystemsSun MicrosystemsSun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
Sun Hydra 3/80, SPARCstation 1SPARCstation 1The SPARCstation 1, or Sun 4/60, is the first of the SPARCstation series of SPARC-based computer workstations sold by Sun Microsystems. It had a distinctive slim enclosure and was first sold in April 1989, with Sun's support for it ending in 1995.Based around a LSI Logic RISC CPU running at...
, SPARCstation 2SPARCstation 2The SPARCstation 2 was a computer workstation. The successor to the SPARCstation 1, it was released in 1990, and manufactured by Sun Microsystems.-Memory:...
, and SPARCstation IPX computer motherboard.
- Various x86-Personal computerPersonal computerA personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...
ISAIndustry Standard ArchitectureIndustry Standard Architecture is a computer bus standard for IBM PC compatible computers introduced with the IBM Personal Computer to support its Intel 8088 microprocessor's 8-bit external data bus and extended to 16 bits for the IBM Personal Computer/AT's Intel 80286 processor...
network interface cardsNetwork cardA network interface controller is a computer hardware component that connects a computer to a computer network....
(some called NE1500 and NE2100 ). Under UnixUnixUnix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
operating systemOperating systemAn operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
s like FreeBSDFreeBSDFreeBSD is a free Unix-like operating system descended from AT&T UNIX via BSD UNIX. Although for legal reasons FreeBSD cannot be called “UNIX”, as the direct descendant of BSD UNIX , FreeBSD’s internals and system APIs are UNIX-compliant...
/NetBSDNetBSDNetBSD is a freely available open source version of the Berkeley Software Distribution Unix operating system. It was the second open source BSD descendant to be formally released, after 386BSD, and continues to be actively developed. The NetBSD project is primarily focused on high quality design,...
/OpenBSDOpenBSDOpenBSD is a Unix-like computer operating system descended from Berkeley Software Distribution , a Unix derivative developed at the University of California, Berkeley. It was forked from NetBSD by project leader Theo de Raadt in late 1995...
/Linux the device driverDevice driverIn computing, a device driver or software driver is a computer program allowing higher-level computer programs to interact with a hardware device....
is usually called le(4).
- QEMUQEMUQEMU is a processor emulator that relies on dynamic binary translation to achieve a reasonable speed while being easy to port on new host CPU architectures....
emulating Sun-4Sun-4Sun-4 is a series of Unix workstations and servers produced by Sun Microsystems, launched in 1987. The original Sun-4 series were VMEbus-based systems similar to the earlier Sun-3 series, but employing microprocessors based on Sun's own SPARC V7 RISC architecture in place of the 68k family...
architecture (sun4m) virtual network interface.
- GXemulGXemulGXemul is a computer architectureemulator being developed by Anders Gavare. It isavailable as free software under a revised BSD-style license.In 2005, Gavare changed the name of the software project...
with le(4) emulating ARMARM architectureARM is a 32-bit reduced instruction set computer instruction set architecture developed by ARM Holdings. It was named the Advanced RISC Machine, and before that, the Acorn RISC Machine. The ARM architecture is the most widely used 32-bit ISA in numbers produced...
, MIPSMIPS architectureMIPS is a reduced instruction set computer instruction set architecture developed by MIPS Technologies . The early MIPS architectures were 32-bit, and later versions were 64-bit...
, M88KMotorola 88000The 88000 is a RISC instruction set architecture developed by Motorola. The 88000 was Motorola's attempt at a home-grown RISC architecture, started in the 1980s. The 88000 arrived on the market some two years after the competing SPARC and MIPS...
, PowerPCPowerPCPowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...
, and SuperHSuperHSuperH is a 32-bit reduced instruction set computer instruction set architecture developed by Hitachi. It is implemented by microcontrollers and microprocessors for embedded systems....
CPU. One example architecture is DECstation 5000 (3max).