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???
10/23/06 09:27
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 		 #126893 - No lock IRQ
Responding to: ???'s previous message
I don't see the need for locking the IRQ.

The mov instruction should not push but just load the register.
When an lcall or ljmp is executed the current bank should be pushed to the separate stack and this register selected as the new current bank.
When an acall is executed the current bank should be pushed on the separate stack.
When a ret is executed the current bank must be popped from the separate stack.
When an interrupt is serviced the current bank must be pushed and bank 0 activated regardless of the contents of this sfr.
When a reti is executed the bank is popped again.
Reading the sfr should give the current bank.

To be able to implement an indirect call you need to be able to push and pop this stack. I think a second sfr is best for this use. Writing it pushes, reading it pops.

Since legacy indirect calls/jumps will not work with this scheme en/disabling the automatic bankswitching is preferred.

List of 59 messages in thread
TopicAuthorDate
How much flash should an 8051 have?            01/01/70 00:00      
   enough            01/01/70 00:00      
      Code Flash VS Data Flash            01/01/70 00:00      
         hints            01/01/70 00:00      
            Max Clock Speed, Etc.            01/01/70 00:00      
               that\'s a cop-out            01/01/70 00:00      
                  Not a cop-out            01/01/70 00:00      
                     can you sell it for less than $1.41            01/01/70 00:00      
                        Replacement costs            01/01/70 00:00      
                           then please stop arguing one point from the perspe            01/01/70 00:00      
                              The replacement market            01/01/70 00:00      
                                 How will that help?            01/01/70 00:00      
                                    Flash Reliability            01/01/70 00:00      
                                       not really - look out            01/01/70 00:00      
                                          More on Flash Reliability            01/01/70 00:00      
                                             XRAM replacement            01/01/70 00:00      
                                                Write-While-Fetch            01/01/70 00:00      
                                    That does not appear to be the target.            01/01/70 00:00      
                                       6/12 Clock Mode and XDATA support            01/01/70 00:00      
                     Have you looked at the one-clockers?            01/01/70 00:00      
                        How do you propose to fit that in the instruction            01/01/70 00:00      
                           map registers            01/01/70 00:00      
               clock speed            01/01/70 00:00      
                  Not a bad idea ... that's what Dallas did!            01/01/70 00:00      
                     Clock Speed Reduction            01/01/70 00:00      
                        if you knew the chip            01/01/70 00:00      
                           actually, it does either speed up or slow-down            01/01/70 00:00      
                              Variable clock speed            01/01/70 00:00      
                                 clock vs power            01/01/70 00:00      
                                    SIngle clock power            01/01/70 00:00      
               when i did this            01/01/70 00:00      
                  0.35u process & 64K            01/01/70 00:00      
         Big Flash - coda and data!            01/01/70 00:00      
            Does Zylogic = Triscend?            01/01/70 00:00      
               Zylogic; Triscend            01/01/70 00:00      
            that should make it clear            01/01/70 00:00      
         Data Apps            01/01/70 00:00      
   bank switching mechanism (RFC)            01/01/70 00:00      
      Bank Switching            01/01/70 00:00      
         that's how it's done traditionally ...            01/01/70 00:00      
         Keil support            01/01/70 00:00      
      bank switching no0t needed            01/01/70 00:00      
         "bank switching no0t needed"            01/01/70 00:00      
            if you read it all            01/01/70 00:00      
               I'd even tend to believe...            01/01/70 00:00      
      No lock IRQ            01/01/70 00:00      
   Parkinson's Law...            01/01/70 00:00      
   The trouble with PLLs            01/01/70 00:00      
      nearly every ARM has a PLL            01/01/70 00:00      
   yeah i understand that            01/01/70 00:00      
      ethernet mac            01/01/70 00:00      
   Dougal was..            01/01/70 00:00      
      Sorry to hear about your misfortune            01/01/70 00:00      
   no not seriously            01/01/70 00:00      
      I don't think he hates you, Jez            01/01/70 00:00      
      That must be the most painful            01/01/70 00:00      
         it's not a killer, but you do notice it            01/01/70 00:00      
   well jasmine can ride him all day            01/01/70 00:00      
   Gives a new meaning to that old interview question            01/01/70 00:00      

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