September 27th, 2012 ~ by admin

EPROM of the Day: AMD AM27C2048 – Shrinking Dies

AMD AM27C2048-150DC – 3 Dies (Click to view larger)

In the semiconductor industry process shrinks are highly sought after.  They result in smaller die sizes for the same part, which results in more chips per wafer, thus increasing revenue.  There are other benefits (typically speed increases and power decreases (aside from leakage)) but from a purely economical stand point, the smaller dies result in more profits.

Rarely do you get to SEE the result of these process changes.  UV-EPROMs fortunately have a window, for erasing them with UV light, that also lets the die be seen.  Here are three AMD AM27C2048 EPROMs.  These are CMOS 2-Mbit EPROM, pretty common in the 1990s.  As you can see that while they are all the same part, the dies are significantly different. While its hard to say for sure without a die analysis, we can make some good estimations based on what foundries AMD had at the time these devices were made.  The first EPROM is date late 1993 which will likely be a 1 micron process.  The second EPROM, dated mid 1997 is a bit smaller, around 20% smaller, which fits with AMD’s 0.8 micron fabs.  The last, and latest, EPROM was made in 1998, likely at the joint AMD-Fujitsu (FASL) plant in Japan.  This would mean it is a 0.5 micron device. The plant was transitioning to 0.35 micron at the time, but that was most likely used for the higher profit Flash memory devices.  By 1998 EPROM’s were on the decline.

Also of note is the different copyrights.  The first two are copyright 1989 while the third is 1997.  Its hard to know for sure (I do not have the microscopes/tools needed to do die analysis) but it is likely the 1 micron to 0.8 micron was an optical shrink. Literally this means that the die (and masks) are scaled down to a new smaller process with no architectural changes.  This is simple and inexpensive.  Sometimes changes will have to be made to support a new process, or make full use of its benefits, so a new layout/masks are made.  This is likely the case with the 1997 copyrighted EPROM.  The design was altered to work with the new, smaller process, and it was significant enough to warrant a new copyright.

Posted in:
EPROM of the Day

February 17th, 2011 ~ by admin

The AMD 2901 Bit Slicer and Second Sourcing

AMD AM2901ADC – 1977

In August 1975 AMD introduced the ’100 ns Bipolar microprocessor.’ This was a bit-slice device. Essentially a 4-bit ALU (like a 74181) with functionality (scratch pad memory and accumulator register) to make it work as a processor that could be scaled to any bit width (using the 2909 sequencer and 2910 controller).  Being made in bipolar allowed for the high speed (10MHz at the time was pretty quick).  The introduction of the 2901 also marked the beginning of the end to the competition int he bit-slice arena.  A combination of marketing, second-sourcing, and a good product allowed AMD to completely dominate the bit-slice market.  Even today most bit-slice designs are based on the 2901 from 35 years ago.

At the time there were several other bit-slice processors on the market.  Intel had the 3002 (a 2-bit design), National’s IMP-8 and IMP-16, and the original TTL 74181 were all bit-slice devices.  MMI (which AMD bought in the 1980′s) had introduced the 6701 4bit slice in 1974, a full year before AMD’s 2901.  TI had the SBP0400A and Motorola the MC10800 (in ECL – 1976). So why with all this competition did AMD come to dominate?

Raytheon AM2901ADC – 1980

Second Sourcing

Second sourcing is the licensing of a design to other companies for them to manufacture, market and sell it.  Sometimes its simply a license to manufacture, sometimes it comes with technical assistance, or even complete mask sets to make the device.  There are three main reasons this is done (or was done back in the day)

 

Guaranteed Availability.

In the 1970′s making IC’s was a relatively new process, one with many bugs, and often reliability issues.  Having a second source was a must to get a big design win. A system design would not want to design a system around a chip that may end up not being available, or not be available in the quantities needed.  Having a second source to get the IC from alleviated this problem.  It gave system designers a stable supply, regardless if the primary source could not keep up, or had a problem.

 

Distribution

Second-sourcing helped solve distribution problems as well.  A company may have an excellent design, but no way to sell it.  Often this was a geography problem.  American companies did not initially have a large presence, or distributors set up, in Europe or Japan.  An American company would often second-source a design to a European company (such as Siemens or Thomson) solely to get their design distributed in that area.

 

Marketing

One of the keys to a processors success is design wins.  It can be the best processor on the market,. but if no one uses it, it will fail.  Having additional companies make, and market the processor vastly increased its exposure.  Second-source companies would also typically make development systems, and other support tools, as well as vast documentation for the processor.  This helped ensure that engineers knew about the processor, how to use it, and whee to get it, ensuring its winning of more sockets.

Soviet Electronika 1804VS1 – 2901 Clone – 1988

AMD clearly understood the importance of second-sourcing.  In November 1975, just months after the 2901 was released, they designed an agreement with Motorola to make the 2901.  In December, they signed up Raytheon, and in March of 1976 AMD signed an agreement with the SESCOSEM division of Thomson-CSF, to make and distribute the 2901 in markets outside the US and Japan. In June 1976 AMD amended their agreement with Motorola to include more technical assistance, ensuring Motorola could get the 2901 to market. In September 1976 MMI canceled the 6701, as they were unable to compete.  MMI had no second-sources for the 6701 which likely led to its failure.

As the years went by, AMD added more second-sources, and dropped a few. Eventually coming to completely dominate the bit-slice market.  The Soviets began to copy the 2901 around 1985 (not particularly legally but they did what they had to) and continued to do so until well into the 90′s.

Year Second Sources
1975 Motorola
1976 Motorola, Raytheon, Thomson
1977 Motorola, Raytheon, Thomson, National
1978 Motorola, Raytheon, National, Fairchild, NEC, Signetics, Thomson
1980 Motorola, Raytheon, National, Fairchild, NEC, OKI (MSM8821?), Thomson
1982 Motorola (2903), National, Fairchild, NEC, Thomson
1985 National, Thomson, Cypress, USSR
1990 Cypress, IDT, Thomson, National, USSR
1995 Cyrpress, IDT, WSI, Thomson, Russia

Innovasic IA59032 – 8 x 2901 – 2003

AMD also made the AM29C101 which was 4 2901s in a single chip, producing a 16bit processor.  Cypress manufactured a copy of the 29C101 called the CY7C9101

Several other companies also designed multiple 2901s into a single chip. WSI (and later InnovASIC) designed the 59032, which has the equivalent of 8 2901s to form a 32 bit slice and the 59016 which was  16bit slice (4x 2901).  IDT designed the 49C402 which was also a 16 bit slicer.  Today the 2901 is still in wide use, and while not generally used for new designs, it still powers a vast amount of electronic equipment that still is in use.  InnovASIC still manufactures the 2901 (in 59032 form) to this day.

November 18th, 2010 ~ by admin

AMD Bobcat splits the Atom to the Core

AMD recently released the Bobcat line of APUs (Accelerated Processing Units).  These are part of their new ‘Fusion’ line which integrates fairly simple, yet fast, CPU cores with Radeon graphics.  Several sites have benchmarked the Bobcat against the Intel Atom and the results are rather amazing. Engadget has a list of benchmarks as well.

AMD Bobcat Fusion APU - Zacate

The dual core 1.6GHz E-350 dissipates a mere 18W, and containing a Radeon 6310 500MHz 80 core GPU.  In various application tasks it handily beats the Intel Atom, and in video tests (gaming etc) its integrated Radeon GPU does remarkably well.  Its good to remember that the E350 (and others in its family) are designed for netbooks, tablets, etc.  Its good to see AMD taking a bite out of Intel’s Atom.  Its this sort of competition that drives technological advances, and makes processors out of date fast enough for CPU collectors to pick them up.

Posted in:
Processor News

April 1st, 2010 ~ by admin

AMD Launches ‘Lottery-Core’ CPUs

AMD today unvelied their new CPUs for gamers, which seem to readily appeal to poker players. The New Lottery Core series contains 12 cores. However, as is normal with production of such a complex device some, or all of these cores may not work.  AMD has designed the cores/CPU such that if a core fails, the others will function fine, this of course saves them testing, as well as packaging costs as each chip can use the same package and markings.

Obviously these are targeted specifically for the hobbiest, and priced accordingly. You may get one with all 12 cores functioning and if so AMD considers you ‘very lucky’ apparently not so much if you get one with no working cores.

Currently these are only available in the UK, but if successful should spread elsewhere.

More Info at PC Pro UK

Tags:

Posted in:
Processor News