***** README.TXT *****

    Latest Tips on the AMCC S5920 Developer's Kit


File: readme.txt in PCIdk\S5920

Revision History

11/1/97  MD   readme.txt for October 1997 S5920DK


1. How to use the documentation...

   Read this file for the latest additions and changes to the 5920DK.
   See the 5920DK Manual in PCIdk\S5920\Docs\DKManual to get started
   with the 5920DK.

2. Conserving hard disk space...
  
   You may NOT need to copy all the files from the CD to your hard disk.  Since all the
   files on the CD-ROM are uncompressed and there is no Setup program, you can be selective, copying
   only those directory trees that you want to CHANGE to your hard drive.  All other trees can be
   used from the CD-ROM drive as read-only files.  

3. For this version of the CD-ROM, do not allow Windows 95 to load a 5920DK device driver...

   For each Windows 95 boot after you have installed the 5920DK in your PC, Windows 95 will prompt you to
   install a device driver for the newly found hardware.  Answer CANCEL to this request, so that you
   do not install a device driver for the 5920DK.

4. Tuning your 'build' environment...

   Before using the Borland or Microsoft IDEs to build the 5920DK source code, you may need to set up
   the IDE's include and library paths for the directory in which you have installed the PCIdk tree.

5. TASM switches can be problematic...

   Building the programs tpci, topr, etc., requires the file io.c to be translated from C to assembler,
   then assembled manually using the Borland assembler TASM.  Be sure to use the following command line
   for tasm:
           tasm /ml io.asm
   The /ml switch forces TASM to put lower-case symbols in io.obj, as required by all callers of the 
   routines in io.obj.

6.0 Check that the 5920 PCI board is enabled...

    If you have difficulty with any of the included programs, the first thing you should
    do is use TPCI to make sure the least significant 2 bits of the
    PCI Command Register are set to 1.  See below for an explanation.

6.1 Windows 95 may disable the 5920DK PCI board...

    If you have difficulty running the included programs in a Windows 95 DOS box,
    switch to MS-DOS.

   One additional way to boot to raw MS-DOS (not mentioned in the DK Manual) is to insert a
   'pause' statement near the start of your autoexec.bat file, then after rebooting:
	 - hit Cntrl C when the autoexec.bat pauses
         - answer Yes to "Terminate batch job (Y/N)?"

   Explanation: The Plug and Play component of Windows 95 (depending on the Service
   Pack version you have installed) disables the 5920DK because it does not know what type of 
   device it is, or because there is no corresponding device driver.

6.2 Your Plug N Play BIOS may disable the 5920DK PCI board...

   Additionally, there may be an similar issue with Plug and Play BIOSs.  You may have to turn off the
   Plug N Play feature of the BIOS by using your BIOS Setup menus.
  
   Explanation: The Plug N Play BIOS scans the PCI bus before the Operating System boots 
   and disables adapters that it does not 'recognize.'

6.3 Other workaround to 6.1 and 6.2...

   Use TPCI to read the PCI Command Register, then write that value back using TPCI
   *** but with the two least significant bits set to 1 ***.

   Explanation: The two low order bits of the PCI Command Register for each PCI Agent are:
	- Memory Space Enable
	- I/O Space Enable.
   These bits are sometimes set to zero by the Plug N Play BIOS or Windows 95 Plug N Play subsystem
   to disable an 'unknown' board.  They *must* be set to 1 to enable the corresponding I/O or Memory spaces
   for any PCI Agent, including the S5920DK. 

7. Expediting your software answers...

   The final tests of this Developer's Kit were run with Borland 5.02 and TASM 5.0.  
   Although we do not anticipate any problems with earlier versions (greater than 4.5), we recommend
   that you upgrade so that we can better answer your technical questions.

8. Borland IDE quirks (cockpit error?)...

   If your Project window mysteriously disappears when using the Borland IDE, simply invoke
   the Project item in the View menu (View | Project).

9. TNV restriction...

   As currently coded, TNV will *only* work with 2 KB nvRAMs (EEPROMs).  
   Currently, you will need to change the code to work with other size nvRAMs.

   AMCCPCI does not have this restriction.   

10. S5920 Data Book errors...

   On p. 6-12 of the S5920 Data Book, in Table 6-2, Byte Offset 50h should read:

      Byte Offset:    50h
      Byte Length:    as per Data Book
      Binary Value:   80h, 81h or 82h  ( *not* C0h, C1h or C2h)
      Description:    as per Data Book
      Example:        as per Data Book

   This fix is reflected in the file nv9.bin in Hardware\5920pci\Eeprom.  
   (The C0h, C1h or C2h would be *correct* for an S5933.)

   
   In the same table (6-2) the Description for Byte Offset 45h should read:

      (see Section 7.1.4.4 *and* 9.8.4)

11. AMCCPCI Caution...

   Make sure if you are programming an S5920 nvRAM that you traverse only the S5920 tree.
   Make sure if you are programming an S5933 nvRAM that you traverse only the S5933 tree.

   If you do otherwise, you may introduce the wrong data into your Memory Image for your given device
   (such as incorrectly writing a C0h, C1h or C2h to an S5920 as in Item 11 above).


12. The password for the 5920 Data Book 5920_ds.pdf is 

            sequence

    the street name of AMCC Headquarters.