[FRAM71] Pre-Production Batch

[Dave Frederickson]

(02-10-2015 02:19 AM)Michael Fehlhammer Wrote:  I have to admit that I didn't really understand Dave's sophisticated considerations, probably it's too late at night right now, but I'd like to contribute a very simple argument why bank switching would be helpful:
I am pretty sure that most of the FRAM71 users have been 71b power users before and own a lot of physical modules, like math and curve fitting, for example, and they certainly use the IL module. These three modules consume 2 * 32k + 48k = 112k of address space, right? If I plug in these modules, 112 (more) kiloBytes of FRAM cannot be used.
If I had a bankswitching mechanism, I could make use of the "hidden" RAM pages.

Correct. Other RAM and ROM's subtract from the FRAM available to the 71B. All 512k of FRAM can't be accessed all at once because of the 71B's 512k addressing limitation. What I think could be done via bank-switching is to disable blocks of FRAM for one configuration and enable different blocks for another configuration. The 71 would configure only the enabled blocks. I would think that it's possible to bank-switch all 16 blocks of FRAM. In reality there's probably something I don't understand about the FRAM71 architecture preventing this.