What does Q 3.12 fractional data type mean?

Q3.12 fractional data type is a fixed-point data type that is commonly used in digital signal processing (DSP) applications. The term "Q" refers to the format of the data type, where "Q" stands for "fixed-point" and the number following it (in this case, 3.12) indicates the number of bits used to represent the integer and fractional parts of the number.

In a Q3.12 fractional data type, there are 3 bits used to represent the integer part of the number and 12 bits used to represent the fractional part of the number. This allows for a range of values between -8 and 7.999, with a resolution of 1/4096 (or approximately 0.00024).

Q3.12 is often used in DSP applications because it provides a good balance between precision and memory usage. It allows for more accurate calculations than integer data types, while requiring less memory than floating-point data types.