TVI Electronics, LLC

[rtaubitz]

 TC51854 Memory

[vivat]

Unfortunately, the current TC51854 firmware will not support AT45DB081D DataFlash memory. There are some differences in AC and DC Characteristics between the AT45DBxxx "B" and new "D" DataFlash families. The new AT45DBxxx "D" DataFlash families require a different communication protocol. Therefore, it will require modification of the firmware .

If you're interested in replacing AT45DB041B with a AT45DB081D DataFlash and modifying the TC51854 controller's firmware, please PM me or email TVI Electronics for further assisstance.

[rtaubitz]

PM sent.

[rtaubitz]

This may help..
"Migrating from the "B" to the New "D" DataFlash Family"
http://www.atmel.com/dyn/resources/prod_documents/doc3644.pdf

[vivat]

I've briefly compared the two datasheets of AT45DB041B and AT45DB081D DataFlash memories. It seems to me that AT45DB081D might work as a replacement for AT45DB041B in current TC51854 configuration. Once you'll get your new xxxxxx081D DataFlash, you can give it a try. If you'll be able to successfully read/write screens, all we'll have to do is modify the firmware and DCA software to support additional 204 screens.

[rtaubitz]

Hopefully that's the case! However, upon reading just the "Main Memory Page Read" section, there are some discrepancies between the two.. Quoting from the datasheet, for the AT45DB041B:

[vivat]

The Atmel documentation is a bit confusing. The 4 don't care bytes requred after the 24-bit page address in AT45DB081D are the same 32 don't care bits in AT45DB041B. So, my guessing is that you will be able to use half of the chip memory without making any firmware modifications.

[rtaubitz]

Ah right! I didn't even see that it says Bytes and Bits! Confusing!

Well that makes more sense now I'll post again once I get the parts and swap over the IC.

Thanks vivat

[rtaubitz]

<del>The AT45DB081's arrived today, I should have a chance to swap them over tonight and will report back if they work straight away or not (tonight probably being 4am UTC-6 time, it's 11AM here)</del>

..left them at work after all that

[rtaubitz]

It works! Without any modification can now save/load pages. However as the fonts were stored in pages 1-4 I now no longer have them Text now just comes up as a line of dots. Is it possible to either have them sent to me, or can I extract them from the other eeprom?

Also now, how could I go about having the firmware updated to recognise the additional pages? (I have an AVRISPmkII programmer so I could update the firmware)

[vivat]

Check your PM for username and password for TC51854 controller firmware download.

It'll take some time to modify the firmware and the DCA software to support the AT45DB081. I'll let you know when it's ready.

[rtaubitz]

Thanks vivat, no problems thanks heaps for your help.

One thing I was wondering about though, is when the page is selected you send Chr ( & Chr (screen number (from 1 to 204)) - obviously the second byte can only go up to 255, so would it then have to be changed so to select screen you send something like Chr ( & Chr (byte2) & Chr (byte1) - eg to select page 300, Chr ( & Chr (1) & Chr (44) or something?

Regards,
Rowan

[vivat]

Hi rtaubitz,

The TC51854 firmware and DCA software are now available to support AT45DB081D flash memory. To download, click the links below. Use your custom access user name and password to download the files.

DCA with 8Mb support
TC51854 firmware with AT45DB081D support

There are two new commands added to the firmware, command 35 and 36.

To store the first 255 screens, use command 17 and screen number from 1 to 255.
To store screens 256-408, use command 35 and screen number minus 255. Example of how to store screen number 256: printf("%c",35);printf("%c",1);

To load first 255 screens from the memory, use command 8 and screen number from 1 to 255.
To load screens 256-408, use command 36 and screen number minus 255. Example of how to load screen number 256: printf("%c",36);printf("%c",1);

[rtaubitz]

Awesome, thanks vivat!

Confirmed working! Thanks again, i'll be sure to buy again from TVI