uC/OS-II, The Real-Time Kernel

                              Atmel AT90/AVR Port

                                 READ ME FILE

------------------------------- IAR C COMPILER --------------------------------

1) The  current  version  of  the Atmel AVR port is based on the IAR C Compiler
   V1.30 and V1.40:

   IAR Systems Software Inc.
   One Maritime Plaza, Suite 1770
   San Francisco, CA 94111
   USA

   415-765-5500
   415-765-5503 (FAX)

   www.iar.com
   info@iar.com

2) It is assumed that the command line version of the IAR compiler is installed
   as described in the User Guide of the compiler.


--------------------------------- AVR PORT NOTES ------------------------------

1) The port installation batch file (INSTALL.BAT) places the AVR  port  in  the
   following directory of the selected drive:

   \SOFTWARE\uCOS-II\AT-AVR\IAR

   This directory contains the following sub-directories:

   \SOFTWARE\uCOS-II\AT-AVR\IAR\SOURCE
       This directory contains the port source files as well as the sample test
       code (i.e. TEST.C)

   \SOFTWARE\uCOS-II\AT-AVR\IAR\TEST
       This directory contains BUILD.BAT which is used to compile, assemble and
       link the test code.

   \SOFTWARE\uCOS-II\AT-AVR\IAR\OBJ
       This  directory  contains the  object files produced by the compiler and
       assembler.

   \SOFTWARE\uCOS-II\AT-AVR\IAR\LST
       This directory contains the 'listing' files produced by the compiler and
       the assembler.  For the C compiler, these files contain the  interleaved
       C source along with the assembly language code generated by the compiler.

   \SOFTWARE\uCOS-II\AT-AVR\IAR\DOC
       Contains  this readme file  and any other  documentation that comes with
       the port.

2) The IAR c-compiler uses two stacks; one return stack (this is the AVR return
   stack indexed by the AVR stack pointer, SP) and a data  stack indexed by the
   Y register (R29:R28).  I have  arbitrary  placed  the  return stack 64 bytes
   below the start of the uC/OS-II stack.  This leaves  448 bytes of data stack
   when the uC/OS-II stack is 512 bytes. Depending on your application this may
   or may not be adequate.  If you have very deep nesting of function calls you
   should increase the size of the return stack. As always when using real time
   operating  systems or kernels, figuring  out  the  boundaries of each task's
   stacks is wise.

   The default stack size is defined by the symbol  OS_TASK_DEF_STK_SIZE in the
   file "os_cfg.h".

3) TIMER0   overflow  interrupt  is  used  to  generate  the  clock  tick  (see
   OS_CPU_A.S90).

4) The code was tested using the  AVR Studio V1.44 AVR simulator available free
   from the Atmel WEB site (www.atmel.com) as well as on a home grown AT90S8515
   board with  32K  of external RAM.  The  port should work equally well on the
   AT90S4414 device as long as enough (external) RAM is  provided.   Note  that
   V1.44 of  AVR  Studio  does not support  C-code in include files. This means
   that if you want to do  source  level  simulation with  AVR  Studio you have
   to manually insert  the uC/OS-II C files (i.e. OS_????.C) into the UCOS_II.C
   file before compiling your project.

5) You will also need the source code for uC/OS-II to recompile  this port. The
   uC/OS-II source is included in Jean Labrosse's book  "MicroC/OS-II, The Real
   Time Kernel". More details can be found on the web page where you downloaded
   this archive.


----------------------------- REPORTING PROBLEMS ------------------------------

If you find a bug in this port, do  not  hesitate  to  report the problem to me
(Ole Saether):

1) Through e-mail: ole.saether@eunet.no

2) By calling me (between 11AM and 4PM Eastern time)

   +47 918 21 540

Make  sure  that the problem  you are reporting is in this port and not in your
application.

Enjoy!!


------------------------------ AVR RELEASE NOTES ------------------------------

June 22, 1999 : V1.01
---------------------

 1) The default stack size is now set by the symbol OS_TASK_DEF_STK_SIZE in the
    file "os_cfg.h".


December 1, 1998: V1.00
-----------------------

 1) First release of AVR port