Email: Password: Remember Me | Create Account (Free)

Back to Subject List

Old thread has been locked -- no new posts accepted in this thread
Jim Granville
01/16/13 19:11
Read: 767 times

#189207 - Some links to reduce work
Responding to: James Brzycki's previous message
James Brzycki said:

To jim, I will look into doing the two eeprom thing as I can get my hands on a multiplexer and more eeproms. And it would be exactly what I asked, sounds rather simplier that the memory connections that I have going now.

To handle the PC end, & most of the handshake stuff, it is best to find existing software.
This page has good general lists
and the link to here
has PC software and source code for PC read/write to parallel pins.

So it is very close to what you need - in code flow terms, it is 100%.
Only the lowest level port writes will need modifies, & strip out all Vpp stuff.

For your pair of EEPROM device, look at SST39SF010A series.
These are cheaper/more avail than 64K parts, and you can jumper wire A16,
as a wear-leveling mechanism.

With 20us single byte writes, (Baud rate is slower) write is easy
Only the 100ms block erase needs a specific delay

You will need to modify that code, to remove all the static Port access, and replace with XDATA Read/Write. (MOVX opcodes)

Place that code (via work programmer) into your ROM wired device (WE#=HI,OE#=PSEN), and wire the RUN device as SRAM. (WE#=WRN, OE#=RDN)
(do not add the Multiplex until this part is all working )

Then edit-and-retry your ROM code, until you can get all these steps



A useful early test, is to comment out the Chip-action-lines inside erase(); write(); lock(); functions (but keep the handshake and delays), and thus test in READ only mode.
Use your programmer to place a known pattern in the RAM part, and give that file to the PC link end.

When you have full link operation, the PC will verify the device against the test pattern file you used to program it.
Then, you can enable Erase action lines, and check you can read FFH's

Finally enable the Write() action lines, & test.
When all that is 100%, do a speed-up pass, to remove the unnecessary delays.
SST39SF010A data will tell you what time is needed.

Finally, add your Multiplexer to flip from Boot Download, to Run.
Then, send your tested & commented code to the Author in link #2.

List of 40 messages in thread
Regarding Typical memory connection for a ds80c320      James Brzycki      01/13/13 19:39      
   drop it!      Erik Malund      01/13/13 20:10      
   same question - same answers      Andy Neil      01/13/13 23:32      
   It won't work      Andy Neil      01/13/13 23:41      
      Andy Neil's previous message      James Brzycki      01/14/13 06:41      
         little feet stamping the floor      Erik Malund      01/14/13 07:33      
            little feet stamping the floor      James Brzycki      01/14/13 07:45      
               Erik doesn't like it when you don't do what he wants      Richard Erlacher      01/14/13 11:11      
                  KISS      Erik Malund      01/14/13 11:39      
                     Not exactly ...      Richard Erlacher      01/14/13 23:35      
                        I find it odd that you      Erik Malund      01/15/13 09:29      
                           just to add      James Brzycki      01/15/13 11:24      
                              If you really want to use ds80c320      Jim Granville      01/15/13 18:28      
                                 Not necessary ...      Andy Neil      01/15/13 23:31      
                                    What about the other option?      Richard Erlacher      01/16/13 02:00      
                                    Yes, but ..      Jim Granville      01/16/13 12:56      
                              So your development cycle will be...      Andy Neil      01/16/13 01:01      
                           What about that other post?      Richard Erlacher      01/16/13 01:50      
                              reply to all      James Brzycki      01/16/13 14:12      
                                 'something'      Erik Malund      01/16/13 15:16      
                                    "something" reply      James Brzycki      01/16/13 16:35      
                                 Some links to reduce work       Jim Granville      01/16/13 19:11      
                                 I'm not surprised ...       Richard Erlacher      01/17/13 01:06      
                                    down memory lane      Erik Malund      01/17/13 09:38      
                                       Antique chips        Mahmood Elnasser      01/17/13 10:04      
                                          in my opinion      Erik Malund      01/17/13 13:06      
                                             Just where, under the hood, can you look?      Richard Erlacher      01/17/13 21:42      
                                                this applies equally well      Erik Malund      01/17/13 21:52      
                                                   Did he say he wants apples?      Richard Erlacher      01/17/13 21:57      
                                          Highly integrated devices deprive one of valuable experience      Richard Erlacher      01/17/13 21:38      
                                       the only difference ...       Richard Erlacher      01/17/13 12:14      
                                          a monitor can not       Erik Malund      01/17/13 13:09      
                                             I don't think anyone's that foolish ...       Richard Erlacher      01/17/13 21:15      
                                                I do      Erik Malund      01/17/13 21:26      
                                                   He doesn't have to apply external memory      Richard Erlacher      01/17/13 21:55      
                                                      by your posts he does      Erik Malund      01/17/13 22:14      
                                                         You have to consider ALL his posts      Richard Erlacher      01/18/13 11:47      
            The bible links      James Brzycki      01/14/13 07:47      
               you are right      Erik Malund      01/14/13 08:07      
                  Thanks      James Brzycki      01/14/13 08:29      

Back to Subject List