Memory Array With Decoder

The processor can usually address a memory space that is much larger than the memory space covered by an individual memory chip. In order to splice a memory device into the address space of the processor, decoding is necessary. For example, the 8088 issues 20-bit addresses for a total of 1MB of memory address space.

In This Chapter we will cover- Memory components RAM memory cells and cell arrays Static RAM-more expensive, but less complex Tree and Matrix decoders-needed for large RAM chips Dynamic RAM-less expensive, but needs quotrefreshingquot Chip organization

Layout-Design-of-an-8x8-SRAM-array The project is about building an 8-row by 8-bit SRAM memory array, using 65nm CMOS technology. Using a 3-to-8 decoder, the SRAM array is accessed by a 3-bit address. The SRAM cells are designed to achieve lowest power consumption and suitable static noise margin, while operating at 100 MHz Read amp Write cycles.

Pre-decode Row Decoder Other circuit tricks for building row decoders Array-Structured Memory

Memory Arrays Memory Arrays Random Access Memory Serial Access Memory Content Addressable Memory CAM ReadWrite Memory RAM Volatile

To build a fast memory, we need to minimize the delay of the decoder. This challenge will serve as a jumping off point for delay estimation and gate sizing to minimize delay.

Memory array architecture 3 When reading, contents of word written to bitlines. 24 Decoder Address 2 11

In digital electronics, the memory decoding process took place, when there is a need to access the memory in digital devices. In the process, the binary addresses are generated, to find the wanted memory in the system. As result, the created memory units, with the help of memory addresses, can find the requested data.

Array Architecture 2n words of 2m bits each If n gtgt m, fold by 2k into fewer rows of more columns wordlines n-k k n column decoder bitline conditioning 2m bits bitlines memory cells 2n-k rows x 2mk columns column circuitry Good regularity - easy to design Very high density if good cells are used

Outline Memory classification Basic building blocks ROM Non Volatile Read Write Memories Static RAM SRAM Dynamic RAM DRAM Memory peripheral circuit Content Addressable Memory CAM Serial access memories Programmable Logic Array Reliability and Yield Memory trends