Extract, reconstruct, simulate … repeat

Extract, reconstruct, simulate … repeat

When I started to search for the random generator the first challenge was the decision where to begin with. Looking at the die, there are not many landmarks that provide clear guidance. The ROMs are quite prominent due to their regular structure, but they don’t...
ROM extraction

ROM extraction

The previous post introduced a tracing procedure to extract logic gates from VLM5030’s layout information. This post shows how the procedure can be extended to extract VLM5030’s embedded ROMs. Simple ROMs The image below shows a portion of the sequencer...
Logic gates extraction

Logic gates extraction

The technology We need to set the stage first for this post. The VLM5030 is built from depletion-load NMOS logic. This means there are basically two types of devices: Enhancement-mode NMOS transistors for shorting a node to GND (or forwarding voltage between two...

Randomness on a microscopic level

Quite a couple of Konami cores use the VLM5030 chip to generate human-like speech for in-game effects. While the replacement design created for the replay library does its job, it still falls behind the audio of an original chip. This is mainly due to the fact that...