Declaring and Defining ap_[u]fixed<> Variables - 2021.2 English - UG1399

There are separate signed and unsigned classes:

• ap_fixed<W,I> (signed)
• ap_ufixed<W,I> (unsigned)

You can create user-defined types with the C/C++ typedef statement:

#include "ap_fixed.h" // use ap_[u]fixed<> types

typedef ap_ufixed<128,32> uint128_t; // 128-bit user defined type, 
 //  32 integer bits