Filter Coefficient Data
滤波器系数使用扩展名为.coe的系数文件提供给FIR编译器。 这是一个ASCII文本文件，带有单行标题，用于定义用于系数数据的数字表示的基数，后跟系数值本身。 对于N抽头滤波器，如图3-36所示。
滤波器系数可以以整数的形式提供，可以是基-10、基-16或基-2表示。系数为10，系数为16，系数为2。这句话的英文原版更好：
The filter coefficients can be supplied as integers in either base-10, base-16, or base-2 representation. This corresponds to coefficient_radix=10, coefficient_radix=16, and coefficient_radix=2 respectively.
觉得原滋原味的英文也挺美。
系数值也可以放在一行上，如图3-37所示。
If you enter signed negative symmetric hexadecimal coefficients, each value should be sign-extended to the boundary of the most significant nibble or hex character. This ensures that coefficient structure inference can be performed correctly (this includes Hilbert transform filter types, which are also negative symmetric).
下面还有一段话，不是很理解，大家一起参考：
Alternatively, the coefficients can be entered as real numbers (specified to a minimum of one decimal place) in base-10 only. If you enter signed negative symmetric hexadecimal coefficients, each value should be sign-extended to the boundary of the most significant nibble or hex character. This ensures that coefficient structure inference can be performed correctly (this includes Hilbert transform filter types, which are also negative symmetric).
或者，系数可以仅作为基数10的实数（指定为最小一位小数）输入。 如果输入有符号的负对称十六进制系数，则应将每个值符号扩展到最高有效半字节或十六进制字符的边界。 这确保了可以正确地执行系数结构推断（这包括希尔伯特变换滤波器类型，其也是负对称的）。
下篇博文预告：
分别介绍下面这些滤波器的系数数据问题
