Email: Password: Remember Me | Create Account (Free)


 

Back to Subject List

Old thread has been locked -- no new posts accepted in this thread
Frieder Ferlemann
06/19/09 14:09
Read: 250 times
Old Europe


 		 #166263 - P3_3 commonly for ROM and RAM to switch banks?
Responding to: Sandeep Gupta's previous message
> I am using Port pin Port 3^3 commonly for ROM and RAM to shuffle between banks

Is P3_3 directly connected to A16 of SRAM/ROM?
Or are some logic gates (using P3_3, PortA15 and possibly A14, A13 as inputs) involved?

How does your (expected) memory map look like?
ROM (32 common + 2*32 switched) kByte and SRAM 2*64 switched kByte or:
ROM (16 common + 2*48 switched) kByte and SRAM (32 common + 2*32 switched) kByte.
or something else?

If a single bit for the switching is used then flash and SRAM are switched concurrently.
So f.e. no xdata access to (the switched part of) SRAM bank 1 data from CODE bank 0.

List of 13 messages in thread
TopicAuthorDate
Code and XDatabanking      Sandeep Gupta      06/16/09 02:55      
   Manually handle a few large variables?      Per Westermark      06/16/09 03:39      
      Code and XDatabanking      Sandeep Gupta      06/19/09 01:54      
         You missed the point!      Andy Neil      06/19/09 06:16      
   Do you *have* to use an 8051?      Andy Neil      06/19/09 02:07      
      Code and XDatabanking      Sandeep Gupta      06/19/09 05:35      
         Fair enough, then!      Andy Neil      06/19/09 06:10      
         no banking      Erik Malund      06/19/09 08:33      
            Cross reference      Andy Neil      06/19/09 08:49      
               Verbiage      Erik Malund      06/19/09 09:48      
   P3_3 commonly for ROM and RAM to switch banks?      Frieder Ferlemann      06/19/09 14:09      
      that will not work      Erik Malund      06/19/09 14:44      
         Interference      Per Westermark      06/19/09 15:05      

Back to Subject List