Circular Buffers
Data rate buffers (FIFos) are often referred to as linear buffers. As soon as all the
Locations in the buffer are full, on more entries are made until the buffer is emptied
This wey none of the ''old'' information is lost. A similar memory system is called a
circular buffer. These memory systems are used to store the last n values entered,
Where n is the numder of memory locations in the buffer. Each time a new value is
written to a circular buffer, it overwrites(replaces) the oldest value. Circular buffers
are addressed by a MOD-n address counter. Consequently, when the highest address
is reached, the address counter will ''wrap around'' and the next location will
de the lowest address. As you recall from Chapter 10, digital filtering and other DSP
operations perfrom calculations using a group of recent samples. Special hardware
included in a DSP allows easy implementation of circular buffers in memory.