Hello Dear Readers,   Today in this second post we will discuss further standard cells. A standard cell consists of a set of transistors and their connections which implements a boolean logic or a storage function. Although it is possible to generate any boolean function using only a NAND (or a NOR) gate, the designs will be more area effective by including other logical gates in the library. The elementary gates such as Buffer, Inverter, NAND, NOR, XOR, and memory cells are often found in any standard library while the rich and fancy libraries contain additional gates with higher complexity such as adders and multipliers. The initial design of a standard cell begins with implementing the functionality of the Cell at the transistor level. The schematic view of a cell is used for this purpose. In addition, schematic views are widely used for simulating and debugging circuits. The schematic of a cell can be represented by symbol view which consists of the input and output port...

   Hello Dear Readers,   Today in this entire series I will give you an idea about how the standard cells library which included layout design of the basics all the gates and circuits is formed. The growing demand for the integration of systems with the maximum possible functionality by combining high performance with a tolerable amount of power dissipation has been driving the development and the modeling of CMOS transistor technologies, especially with the growth of the embedded and portable devices market. The need for integration of more and more components onto a single chip, by improving performance with reasonable energy loss, motivated the migration to the deep sub-micron regime. The key success factor for the rapid growth of the integrated system is the use of ASIC library for various system functions. It consists of pre-designed and pre-verified logic blocks that help designers to shorten product development time and manage the complexity of a chip having millio...

Hello Dear Readers,   Today, I will explain how binary, gray, one-hot encoding FSM design using Verilog HDL. 1). Binary Encoding: Binary encoding style can be used if the area requirement is a constraint on the design. In this encoding style state parameters for the binary encoding are represented in the binary format. Two-Bit Binary Up-Counter FSM: Two-bit binary counter FSM is described below, the number of states is equal to 4 and it needs four state variables ‘s0,’ ‘s1,’ ‘s2,’ and ‘s3.’ The number of flip-flops used to represent the functionality of the counter is equal to 2. The state transition table and the state transition diagram is shown in Fig.1 and Fig.2. The transition from one state to another state occurs on the positive edge of the clock. The default state is ‘s0’ and it is the reset state. So outcome is Moore machine as the output is a function of the current state only. Fig.1 State Transition Table Fig.2 State Diagram Verilog Code: module binary_cou...

  Hello Dear Readers, Today, I will explain what are the issues in the mixed-signal circuit layout which is needed to keep in mind while designing the system. Naturally, analog ICs are more sensitive to noise than digital ICs. For any analog design to be successful, careful attention must be paid to layout issues, particularly in a digital environment. Sensitive analog nodes must be protected and shielded from any potential noise sources. Grounding and power supply routing must also be considered when using digital and analog circuitry on the same substrate. Since a majority of ADCs using switches controlled by digital signals, separate routing channels must be provided for each type of signal. Techniques used to increase the success of mixed-signal designs vary in complexity and priority. Strategies regarding the systemwide minimization of noise should always be considered foremost. A mixed-signal layout strategy can be modeled as seen in Fig.1. The lowest issues are foundational ...