TC51854 Memory

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rtaubitz

TC51854 Memory

Post by rtaubitz » Mon Apr 07, 2008 3:32 pm

Hi, I recently got a TC51854 and I have a quick question regarding memory. Is it possible to easily replace the AT45DB041B onboard with a AT45DB081D? This would effectively double the memory, and allow up to 410 pages to be stored :D Very Happy How much modification would need to be made to get this to work or could I pay for the firmware update and replace the chip myself? (they're about $1.80 from digikey..)

Thanks for a great product btw!



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Re: TC51854 Memory

Post by vivat » Mon Apr 07, 2008 4:08 pm

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.


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Re: TC51854 Memory

Post by rtaubitz » Mon Apr 07, 2008 8:40 pm

This may help..
"Migrating from the "B" to the New "D" DataFlash Family"
http://www.atmel.com/dyn/resources/prod ... oc3644.pdf" onclick="window.open(this.href);return false;



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Re: TC51854 Memory

Post by vivat » Tue Apr 08, 2008 12:51 pm

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.


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Re: TC51854 Memory

Post by rtaubitz » Tue Apr 08, 2008 3:47 pm

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:

Code: Select all

To start a page read, an opcode of 52H or D2H must be clocked into the device followed by 24 address bits and 32 don’t care bits.

And for the AT45DB081D:

Code: Select all

To start a page read from the DataFlash standard page size (264 bytes), an opcode of D2H must be clocked into the device followed by three address bytes (which comprise the 24-bit page and byte address sequence) and 4 don’t care bytes.

Same opcode, however less don't care bits to be clocked in after the 24-bit address...

Code: Select all

The don’t care bytes that follow the address bytes are sent to initialize the read operation. Following the don’t care bytes, additional pulses on SCK result in data being output on the SO (serial output) pin.	
So, after 4 don't care bit's it will already start putting the data onto the SO pin, so with the current firmware it might ignore the first 28 bits. This shouldn't be too hard to change in the firmware.

The Write to Buffer etc procedures experiences similar differences, which is odd because that Atmel App Note posted above says the B to D devices are backward compatible..?!



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Re: TC51854 Memory

Post by vivat » Tue Apr 08, 2008 5:23 pm

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.


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Re: TC51854 Memory

Post by rtaubitz » Tue Apr 08, 2008 9:07 pm

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

Re: TC51854 Memory

Post by rtaubitz » Fri Apr 11, 2008 3:35 pm

<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 Smile (tonight probably being 4am UTC-6 time, it's 11AM here)</del>

..left them at work after all that :(



rtaubitz

Re: TC51854 Memory

Post by rtaubitz » Sat Apr 12, 2008 8:38 pm

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)



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Re: TC51854 Memory

Post by vivat » Sun Apr 13, 2008 1:26 pm

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.


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Re: TC51854 Memory

Post by rtaubitz » Sun Apr 13, 2008 10:28 pm

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 (8) & 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 (8) & Chr (byte2) & Chr (byte1) - eg to select page 300, Chr (8) & Chr (1) & Chr (44) or something?

Regards,
Rowan



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Re: TC51854 Memory

Post by vivat » Tue Apr 15, 2008 5:14 pm

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);


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Re: TC51854 Memory

Post by rtaubitz » Wed Apr 16, 2008 6:43 pm

:D Awesome, thanks vivat!

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



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