Chapter 4: Security Architecture and Design - Memory Types

For this section of chapter 4, I want to discuss the various types of Random Access Memory (RAM). Prior to this reading, I was not aware that so many different types existed. With Dynamic RAM, it must be continually refreshed so that the capacitor does not lose its electrons and become corrupt. Since all of this refreshing has to take place, it is slower than static RAM. Static RAM does not have to refresh all of the time, which in turn makes it faster. However, more transistors are required in order to use it. After these two basic types of RAM there are four more. Synchronous DRAM which connects with the CPU so that the timing is right, which in turn makes executing data faster. Extended data out DRAM allows the next bit of data to get ready while the current data is being sent to the CPU. I kind of like to refer to this as "On Deck RAM". Just like a batter in baseball is preparing to step into the batter's box as the current batter is hitting. Burst EDO DRAM does exactly what it sounds like. It is capable of sending bursts of data. A type of RAM that can double the speed of SDRAM is called Double data rate SDRAM. It carries out two operations per clock cycle.