def _get_rw_functions(reg_name, reg_base, nwords, busword, read_only):
    r = ""

    r += "#define CSR_"+reg_name.upper()+"_ADDR "+hex(reg_base)+"\n"
    r += "#define CSR_"+reg_name.upper()+"_SIZE "+str(nwords)+"\n"

    size = nwords*busword
    if size > 64:
        return r
    elif size > 32:
        ctype = "unsigned long long int"
    elif size > 16:
        ctype = "unsigned int"
    elif size > 8:
        ctype = "unsigned short int"
    else:
        ctype = "unsigned char"