What is 16 bit array indexing of code space arrays and why is this different to 8 bit indexing of data arrays? The XCSB compiler optimises data and code space array indexing when it can by generating fast 8 bit code (see fast 8 bit indexing). Because code space arrays can be bigger that 256 elements, XCSB will also generate 16 bit indexing code to access large arrays in the code space when required. Many PIC BASIC compilers do not support code space arrays (large or small), relying on READ and DATA statements instead. In contrast the XCSB code space arrays are far more flexible and easier to use. (see what is a code space array)