Base matrix crystal

Base matrix chip (BMC) ( eng. Gate array , eng. Uncommited Logic Array, ULA ) - a large integrated circuit . Unlike FPGAs, it is programmed technologically by applying a mask to the compounds of the last metallization layer. BMK with a customer mask were usually made to order.

The advantage of BMK is as follows. The developer needs to use original LSI based circuitry, but existing LSIs are not suitable for this purpose. Develop from scratch and produce a very long time, inefficient and expensive. The way out is to use basic matrix crystals that are already designed and manufactured. The base matrix crystal resembles a library of routines and functions for programming languages. Elementary circuits and logical elements are divorced on it, but not connected. The customer develops a wiring diagram, the so-called mask. This mask is applied as the last layer on the base matrix crystal, and elementary circuits and scattered chains on the BMC are combined into one large scheme. As a result, the customer receives a ready-made LSI, which is not much more expensive than the original BMK.

The main application of BMK is computer facilities, process control systems. Some BMKs, for example T34VG1 (KA1515XM1 -216), were used in the Soviet versions of the ZX Spectrum computer as a controller of external devices. An analogue of BMK is the ULA chip in Sinclair computers. Currently, BMK in most applications is replaced by FPGA , which do not require a factory production process for programming and allow reprogramming.

In Russia, basic matrix crystals are produced by Angstrem OJSC , NPO Physics and a number of other enterprises.