February 2, 2015

Reverse-engineering of KR580VM80A / i8080 is complete!

We are glad to announce that reverse engineering of KR580VM80A (the most popular CPU in the exUSSR, Intel 8080-compatible) is finally complete. Insane engineer Vslav (1801ВМ1@gmail.com) recovered full schematic in a very short time. After we got annotation and sorted out license (CC-BY-3.0) - it is available for everyone to enjoy.

It appeared that it had exactly 4758 transistors (contrary to rumors of 6000 or 4500).

Layout of KR580VM80A is quite similar though not identical to i8080, but there were no differing (vs i8080) opcodes identified.

Verilog model of KR580VM80A passed tough compatibility test both in simulation and as FPGA replacing actual KR580VM80A in "Specialist" computer.

Download links: Main verilog, Schematic, Full package.

Die annotation:
February 2, 2015

NXP 74AHC00 : Weekend die-shot

What is the simplest possible microchip? Probably it's 7400 - quad 2-input NAND gate. We made a die shot of NXP's 74AHC00 (AHC means "fast" CMOS). This is a nice example that 'old' tech nodes (1µm and older) are still in use. Also, note how many spare via are there.

Die size - 944x854 µm.

Update 02.02.2015: We redid this chip with better quality. Original photo (September 2, 2012). Looking at the quality difference gives me a warm feeling, 2.5 years well spent...
January 23, 2015

MC34063 : Weekend die-shot

MC34063 is by far the most widespread DC-DC switching regulator.

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January 8, 2015

Noname MMBT3904 - npn BJT transistor : weekend die-shot

On the first glance it looks very similar to NXP PMST3904, but topology is clearly redrawn. Notice sketchy borders of metalization - apparently they were using lift-off process for metalization instead of plasma etching. But for discrete transistors this might still be acceptable for good yield.

Die size 290x291 µm, which is slightly larger than NXP's one.

January 8, 2015
December 21, 2014

KR1818VG93 - FDD controller : weekend die-shot

Enthusiasts started yet another reverse engineering project of KR1818VG93 - FDD controller manufactured in USSR times. Presumably it has some compatibility/similarity with FDC1793-02 - this will be figured out.

Die size 4817x4794 µm, 6µm NMOS technology.

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November 17, 2014

Torex XC6206 - CMOS LDO : weekend die-shot

Torex XC6206 is a popular and really tiny CMOS LDO, especially if you compare it to older bipolar ones, which were magnitude larger. 250mA LDO in SOT-23 might be hard to believe at first.

Datasheet mentions "laser trimming" but we see voltage set via mask and 2 fuses for fine tuning. It is possible though that they have common values set in mask (like this 3.3V one) , and rare voltages laser trimmed.

Die size 500x356 µm, 500nm technology.

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