Limitations

Keil development development tools without a current product license run as a Lite/Evaluation edition and have the following restrictions:

MDK-Lite Edition

Programs that generate more than 32 Kbytes of code and data will not compile, assemble, or link.
The debugger supports programs that are 32 Kbytes or smaller.
The compiler does not generate a disassembly listing of the machine code generated. The -S, --asm, and --interleave compiler command-line options are disabled. Projects will not compile with Target -> Listing -> C Compiler Listing enabled.
The compiler and assembler do not generate position-independent code or data. The --apcs /ropi /rwpi /pic/ pid compiler and assembler command line options are disabled.
The assembler and linker create Symbolic Output Format objects which cannot be linked with third-party linker utilities. Fully licensed tools generate standard ELF/DWARF files which may be used with third-party utilities.
Arm7/Arm9/Cortex-R4 devices are not supported.

The 8051 compiler, assembler, linker, and debugger are limited to 2 Kbytes of object code. Source code may be of any size.
Programs that generate more than 2 Kbytes of object code will not compile, assemble, or link.
The debugger supports programs that are 2 Kbytes or smaller.
The startup code generated includes LJMPs. Code generated cannot be used in single-chip devices that support 2 Kbytes or less of program space.
Programs start at offset 0x0800. Programs generated with the evaluation software may not be programmed into single-chip devices with less than 2 Kbytes of on-chip ROM.
No hardware support for multiple DPTR registers is provided.
No support for floating-point arithmetic and no support for user libraries is provided.
No support for in-line assembly using #pragma ASM.
The following components which are present in the PK51 Full Version are not included in the Evaluation Version: Linker for Code Banking and RTX51 Tiny Real-time Operating System.

The 251 compiler, assembler, linker, and debugger are limited to 2 Kbytes of object code. Source code may be of any size.
Programs that generate more than 2 Kbytes of object code will not compile, assemble, or link.
The debugger supports programs that are 2 Kbytes or smaller.

The C166 compiler, assembler, and linker are limited to 4 Kbytes of object code. Source code may be of any size.
Programs that generate more than 4 Kbytes of object code will not compile, assemble, or link.
The debugger supports programs that are 8 Kbytes or smaller.