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Philldapill
04-05-2009, 05:39 AM
Hey guys, just curious if THIS (http://www.st.com/stonline/products/literature/ds/6757/m24256-br.pdf)eeprom could serve as a replacement for the normal 24LC256 (http://www.parallax.com/Portals/0/Downloads/docs/prod/oem/24LC256.pdf)that is commonly used for the Prop.

The pinout seems to be the same, except the WP pin on the 24LC256 seems to be WC(active low) on the other chip. They seem to be functionally equivalent, but I'd like some insight from the experts.

Post Edited (Philldapill) : 4/4/2009 10:44:33 PM GMT

Mike Green
04-05-2009, 05:44 AM
It looks the same to me. WP and WC is not any different except for the name. If it's allowed to float or connected to Vss, the array can be written. If it's connected to Vdd, the memory array is protected.

Oldbitcollector (Jeff)
04-05-2009, 05:51 AM
512K.. wow.. Gotta look and see if HAM supports that.

OBC

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Mike Green
04-05-2009, 05:52 AM
OBC, remember that EEPROMs are described in terms of the number of bits stored, not the number of bytes.

Oldbitcollector (Jeff)
04-05-2009, 06:33 AM
Ouch.. Just for a moment there I was imagining all the 32k binaries that could
be stored in 512K. (Looking at that datasheet again I see what you mean.)

Thanks for taking all the wind out of my sails Mike.. :)

OBC

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Cluso99
04-05-2009, 06:58 AM
OBC: the spi (incompatible but still 8 pin) W25X80 is 1MB (8Mb) and is also available in 4MB and 8MB Flash - used on the TriBladeProp - and you can read 2 bits at a time if you want. Just cannot boot the prop from it :-(

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Links to other interesting threads:

· Home of the MultiBladeProps: TriBladeProp (http://forums.parallax.com/showthread.php?p=786418), SixBladeProp (http://forums.parallax.com/showthread.php?p=780033), website (Multiple propeller pcbs) (http://bluemagic.biz/cluso.htm)
· Single Board Computer:·3 Propeller ICs·and a·TriBladeProp board (ZiCog Z80 Emulator) (http://forums.parallax.com/showthread.php?p=790917)
· Prop Tools under Development or Completed (Index) (http://forums.parallax.com/showthread.php?p=753439)
· Emulators: Micros eg Altair, and Terminals eg VT100 (Index (http://forums.parallax.com/showthread.php?p=778427))
· Search the Propeller forums (via Google) (http://search.parallax.com/search?site=parallax&client=parallax&output=xml_no_dtd&proxystylesheet=parallax&proxycustom=<HOME/>&ie=&oe=&lr=)
My cruising website is: ·www.bluemagic.biz (http://www.bluemagic.biz)·· MultiBladeProp is: www.bluemagic.biz/cluso.htm (http://www.bluemagic.biz/cluso.htm)

Cluso99
04-05-2009, 07:22 AM
There is an AT24C1024 1024Kb (128KByte). I have one for my TriBladeProp (untested yet)

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Links to other interesting threads:

· Home of the MultiBladeProps: TriBladeProp (http://forums.parallax.com/showthread.php?p=786418), SixBladeProp (http://forums.parallax.com/showthread.php?p=780033), website (Multiple propeller pcbs) (http://bluemagic.biz/cluso.htm)
· Single Board Computer:·3 Propeller ICs·and a·TriBladeProp board (ZiCog Z80 Emulator) (http://forums.parallax.com/showthread.php?p=790917)
· Prop Tools under Development or Completed (Index) (http://forums.parallax.com/showthread.php?p=753439)
· Emulators: Micros eg Altair, and Terminals eg VT100 (Index (http://forums.parallax.com/showthread.php?p=778427))
· Search the Propeller forums (via Google) (http://search.parallax.com/search?site=parallax&client=parallax&output=xml_no_dtd&proxystylesheet=parallax&proxycustom=<HOME/>&ie=&oe=&lr=)
My cruising website is: ·www.bluemagic.biz (http://www.bluemagic.biz)·· MultiBladeProp is: www.bluemagic.biz/cluso.htm (http://www.bluemagic.biz/cluso.htm)

virtuPIC
04-05-2009, 02:47 PM
You have to take care that the prop bootloader doesn't outperform the chip. M24256 can only handle a clock rate of 400 kHz. Okay, I don't know how fast the prop will shake its pins. And the Microchip memory used on my demo board also has a maximum clock rate of 400 kHz. And it works.

Regarding the W25Xnn SPI chips: There is also a W25X16 chip (even in DIL package) holding 2 MBytes. Bill just has published a driver in this forum and I am currently converting it from SPI to assembler.

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Cluso99
04-05-2009, 07:35 PM
Thanks virtuPIC. I don't know why I forgot the W25X16 - it's on the same datasheet as the X32 & X64.

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Links to other interesting threads:

· Home of the MultiBladeProps: TriBladeProp (http://forums.parallax.com/showthread.php?p=786418), SixBladeProp (http://forums.parallax.com/showthread.php?p=780033), website (Multiple propeller pcbs) (http://bluemagic.biz/cluso.htm)
· Single Board Computer:·3 Propeller ICs·and a·TriBladeProp board (ZiCog Z80 Emulator) (http://forums.parallax.com/showthread.php?p=790917)
· Prop Tools under Development or Completed (Index) (http://forums.parallax.com/showthread.php?p=753439)
· Emulators: Micros eg Altair, and Terminals eg VT100 (Index (http://forums.parallax.com/showthread.php?p=778427))
· Search the Propeller forums (via Google) (http://search.parallax.com/search?site=parallax&client=parallax&output=xml_no_dtd&proxystylesheet=parallax&proxycustom=<HOME/>&ie=&oe=&lr=)
My cruising website is: ·www.bluemagic.biz (http://www.bluemagic.biz)·· MultiBladeProp is: www.bluemagic.biz/cluso.htm (http://www.bluemagic.biz/cluso.htm)