2009-09-18 07:10:20     Extend bf537-ezkit design to use 8 MB parallel NOR flash

2009-09-18 07:10:20     Extend bf537-ezkit design to use 8 MB parallel NOR flash

Sebastian Beyer (GERMANY)

Message: 80134   

hi,

we have a custom built board based on the bf537-ezkit design. Due to a lack of flash space we decided to use the gpio-addr-flash driver to extend the 4 MB flash to 8 MB in a future release. We use all 4 AMS lines (AMS0..AMS3) to connect the flash exactly as shown up in the ezkit schematic with all the bank switching via external logic circuits (except the additional dip switch of course).

Our question is: Where to connect the additional GPIO line? The 4 MB flash (S29GL032A) has 21 address lines. A 8 MB type 22 lines. Is the new GPIO connected to the 22nd line or does the AMS bank switching move up to line 21/22 to make space for the GPIO line to connect to line 20?

Thanks in advance!

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2009-09-18 09:32:25     Re: Extend bf537-ezkit design to use 8 MB parallel NOR flash

Mike Frysinger (UNITED STATES)

Message: 80141   

the GPIOs should always be the highest lines.  if you think about it, if you're reading a chunk of flash, which lines are going to be toggled the most and which are going to be toggled the least ?  considering you have to emulate in software the GPIO address lines, it would stand to reason you'd want the least used lines to be the GPIO ones.

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2009-09-18 09:32:56     Re: Extend bf537-ezkit design to use 8 MB parallel NOR flash

Mike Frysinger (UNITED STATES)

Message: 80142   

also, you can look at the schematics for the tiny board modules to see how they've done it

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2009-09-18 09:47:05     Re: Extend bf537-ezkit design to use 8 MB parallel NOR flash

Sebastian Beyer (GERMANY)

Message: 80143   

Tanks a lot. That makes it clear to me.

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2009-09-21 03:35:40     Re: Extend bf537-ezkit design to use 8 MB parallel NOR flash

Sebastian Beyer (GERMANY)

Message: 80183   

Sorry one more question. Do you mean the tinyboard Blackfin modules from Bluetechnix like the CM-BF527? I can only find a document called CM-BF527_HardwareUserManual.pdf which provides some outlines about GPIOs and corresponding Flash address lines but no whole board schematics.

Please could you provide a link?

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2009-09-21 09:29:22     Re: Extend bf537-ezkit design to use 8 MB parallel NOR flash

Mike Frysinger (UNITED STATES)

Message: 80191   

you'll have to ask the BT guys for info.  we dont have anything to do with development of those boards.