Turbo Pascal for 8051 microcontrollers
Pascal is easy to write and easy to read
Turbo51 is a free Pascal compiler for the 8051 family of microcontrollers. If you are programming for the 8051 family of microcontrollers and you like Pascal programming language then you will love Turbo51.
Main features:
Win32 console application
Fast single-pass optimizing compiler
Borland Turbo Pascal 7 syntax
Full floating point support
Mixed Pascal and assembler code
Full use of register banks
Advanced multi-pass optimizer
Smart linker
Generates compact high quality code
Output formats: BIN, HEX, OMF
Assembler source code generation
Source-level debugging with absolute
OMF-51 extended object file
 
Used optimizations:
Constant folding
Integer arithmetic optimizations
Dead code elimination
Branch elimination
Code-block reordering
Loop-invariant code motion
Loop inversion
Induction variable elimination
Instruction selection
Instruction combining
Register allocation
Common subexpression elimination
Peephole optimization
Turbo51 is released as a freeware. You can use Turbo51 for hobby projects and for serious work. Check documentation pages and code examples that show the syntax, features and generated files. This should be enough to start a 8051 project development with Turbo51. And if you are still missing something or have a problem you can always ask for help.
If you are already familiar with 8051 assembly language programming you can start with Turbo51 as 8051 assembly language compiler and then add some Pascal statements until you become familiar with Turbo51 and Pascal syntax. A good approach is also to compile some Pascal code and then check generated code (ASM file). This way you can learn assembly language, get some ideas on how to write effective code and become familiar with the compiler. Turbo51, like many popular C compilers for 8051, generates optimized code and supports source-level debugging with OMF object file.
Program Turbo51;
 
Uses FastCompiler, AdvancedOptimizations, SmartLinker, AssemblerFileGenerator;
 
//  Turbo51 is released as freeware. You can download it and use it for FREE.
//  However, if you like Turbo51 you can donate some small amount via PayPal.
//  Donations are a great way to show your appreciation for my software.
 
begin
DownloadFrom ('http://turbo51.com/download-free-pascal-compiler-8051');
InstallAndConfigure;
Repeat
CreateProject;
CompileProject;
TestProject;
While ThereIsAProblem do
begin
CheckCode;
CheckDocumentation;
TryAgain;
Case ProblemSolved of
True: Break;
else  AskForHelp;
end;
end;
If InstalledVersion < '0.1.3.17' then Update;
If Satisfied then Donate ($20);
until NoMoreProjects;
end. 
 
Turbo51 Download
Download Turbo51
Free Pascal compiler for 8051
Here you can download the latest version of Turbo51 - a free Pascal compiler for 8051. Installation is very simple: just unzip downloaded file with it's folder structure. It is a good idea to include path to Turbo51.exe in the system PATH variable. To write your code you can use any IDE or editor of your choice. You can find some proposals on the IDEpage.

Before you download and install Turbo51 you should read and accept the License Agreement. Turbo51 is released as a freeware. Developing it takes up a considerable amount of my time. If you are using Turbo51 for commercial projects or just like Turbo51 and you would like to support further development, you can donate some small amount via PayPal. Donations are a great way to show your appreciation for my work. Besides being an incredible boost to my morale, they are also a great incentive to fix any bug you find in my software and to add new features.
 
 
Turbo51
Version 0.1.3.17, released 25.06.2013
Fixed bug: Wrong register optimization in some rare code patterns involving Rn
Fixed bug: Wrong comparison (= and <>) for real values in some cases
Fixed bug: Compiler crashed in some cases when using function Abs with integer variables
Fixed bug: Temporary variables used by some procedures in the System unit were not saved during interrupts
Fixed bug: Error reported in assembler statements with relative jump and bit variable located in bit-addresable byte
This is the latest version

http://turbo51.com/