Code banking

dh2 · ‎2004-01-06

Posted on January 06, 2004 at 09:59

Code banking

dh2 · ‎2011-05-17

Posted on May 17, 2011 at 11:57

Hi!

I want to do the as follows:

Reserve the address range from E000 to FFFF for code banking where I map 4 parts of one 32kByte page of the primary flash into by using some bits of the page register for switching the bank.

The principle is quite clear and I would not have any problem if I map 8 kByte pages of the secondary frlash into this address range but when using parts of one 32 kByte primary flash I would have to tell PSD-Express the ''offset'' (0, 2000, 4000, and 6000) of the used part in conjunction with the corresponding page register bits.

I do not have any idea how to solve that problem and appreciate any help.

Thanks in advance.

Herbert

jdaniel · ‎2011-05-17

Posted on May 17, 2011 at 11:57

Herbert,

The uPSDs have only a single internal chip-select signal for each 32kB block of primary flash. I'm pretty sure this means that what you're attempting is not going to be possible. No matter what you have for the chip-select equations, if that bank is selected and the address bus is in the range E000-FFFF, it's always going to access the same location in that flash block.

Best Regards,

pHaze426