Modernization over Time:
Even though this technology was being worked upon since the early 60s and continued well into the 70s, their practical importance grew recently and most digital logic functions such as multiplexers, adders, comparators, decoders etc are based on TTL. Thousands of gates were able to be fitted to a single chip within the late 80s, through which, various PLDs or Programmable Logic Devices were formed.
PLDs use an array consisting of large numbers with AND, NOT and OR gates being arranged in a single design type, connected in a predefined manner. The 1980s saw huge developments being made to this field and a completely new architecture was added during this time frame. This structure used RAM based lookup tables instead of the conventional AND, NOT and OR logic. This device was known as FPAGs or Field Programmable Gate Arrays.
Current Methods of Circuit Designing:
Its basic layout was an array of CLBs or Configurable Logic Blocks, surrounded by an array of Input Output blocks. DCMs or Digital Clock Manager is best suited to diminish the effects of clock distribution delay, which is used to either increase or decrease a clock’s frequency. Drawing logic diagrams is the actual way of designing digital circuits that contain MSI or SSI logic functions.
At a Glance:
With the addition of LSI and VLSI logic circuits however, this process began to pose unforeseen problems. It was practically impossible to draw a structure consisting of Millions of transistors. This led to the evolution of Computer Aided equipments that could reduce human effort. This is how digital circuits are designed today. Many of the other designing techniques that were important during the age of TTL chips have also been out of commission for a very long time.