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miky_boy
Joined: 11 Jan 2008 Posts: 8
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Save 24Kbytes of data |
Posted: Fri Aug 01, 2008 9:29 am |
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Hi to all.
In my project i have to save 6K samples of four adc inputs in pic.
So the the data have the great number of 24Kbytes to save.
I had tested many solutions, external e2prom 24FF1025 in software, and hardware too, save data in ROM, and now i tested with 25LC512, and the problem is the same... it's very slow to save....I know that it's to much data to save, but...i don't know how i saolve this problem..
I tested all this solutions and nothing is good :S
I don't know how i can do this...to make it a little fast..
If any body have any ideia or solution it's very wellcome, and i will very appreciate.
Very thank's to all in advice.
Strong regards,
Miky |
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PCM programmer
Joined: 06 Sep 2003 Posts: 21708
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Posted: Fri Aug 01, 2008 10:18 am |
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Use Page mode to write blocks of data to the eeprom, instead of writing
individual bytes. Page mode is much faster than writing individual bytes.
Page mode is described in the eeprom data sheet. |
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miky_boy
Joined: 11 Jan 2008 Posts: 8
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Posted: Sat Aug 02, 2008 7:22 am |
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Hi my friend, talk to your help, yes i thinked about it, but it only can write 127bytes to buffer. I have to send a lot of then.
To write 6K it takes aroud 12 seconds, with 24FC1024 and 40MhzCrystal in pic.
I triyed to remove the acknowledge byte witouth sucess. I see that it makes a while loop to wait...maybe can incriese that time...
If any other ideia i will appreciate.
Thank's,
Miky |
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ckielstra
Joined: 18 Mar 2004 Posts: 3680 Location: The Netherlands
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Posted: Sat Aug 02, 2008 11:17 am |
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I can't find the datasheet for the 24FC1024, only references to this chip being obsolete.
From the 25LC512 datasheet:
Quote: | Max. 5ms for a 128 bytes byte or page. | Note that writing a single byte or a whole page takes the same time.
Writing in page mode then takes a maximum time of: (6k/128) * 5ms = 240ms |
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Ttelmah Guest
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Posted: Sun Aug 03, 2008 8:24 am |
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Other comment, switch to using a FRAM.
In particular the SPI interface versions, as opposed to I2C. FM25C512 (or L for 3.3v). Zero wait on writes. Speed is limited by how fast you can put the data across the SPI bus.
Means you don't have to worry about pages etc..
Best Wishes |
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