Computers as Components, 2nd Edition

5.1 Components for Embedded Programs 213

change, we can use a fixed-size buffer to hold the current data. To avoid constantly

copying data within the buffer, we will move the head of the buffer in time. The

buffer points to the location at which the next sample will be placed;every time we

add a sample, we automatically overwrite the oldest sample, which is the one that

needs to be thrown out. When the pointer gets to the end of the buffer, it wraps

around to the top. Programming Example 5.2 provides an ef ficient implementation

of a circular buffer.

Programming Example 5.2

A circular buffer implementation of an FIR filter

Appearing below are the declarations ...