Performance evaluation of CCD chip organizations from memory system design viewpoint

This paper discusses the computer memory system design implications of different CCD devices, such as Circulating Shift Register, Serial Parallel Serial, and Line Addressable Organizations.

The performance of the memory using these devices is evaluated in a stand alone mode using a single server queuing model, and as a buffer between the disk and main memory in a computer system by using a two server cyclic queuing model. The performance of the stand alone mode for CCD memory system is defined as the time elapsed between the request for a record and the completion of that request. The performance comparison of stand alone mode shows that Serial Parallel Serial Organization has the worst performance as one should expect. It is shown that the Circulating Shift Register with burst mode for refreshing has better performance than the Line Addressable Organization. Circulating Shift Register Organization with cache has the best performance of all but would require a considerable amount of extra cost.

In evaluating the CCD chip organizations as a buffer between the disk and the main memory, it is shown that all the three organizations (Serial Parallel Serial, Circulating Shift Register, and Line Addressable) have a place in a memory system design depending on the user requirements. It is also shown that a three level (Bipolar, MOS and CCD) memory system using the different CCD chip organizations has a considerable advantage in performance over a two level (Bipolar, MOS) organization for the same total cost.