Hello, i have a bit of difficulty understanding the mega memory map document '' Variable Map Ver9a.pdf '' for the RAM section with SFR.
The info does not pop out clearly. I have used bptr, poke, peek and understand these commands. Normally i experiment and research a lot before asking help but there are warnings not to mess with SFR's and risk frying Picaxes so i need some guidance and forum wisdom please!
Here is what i don't understand:
For example, in PE, the 08m2 has user ram 0-127, including variables b0-b27. The map Ver9a.pdf shows something different from 0 to 255 with SFR sections, comments like:
'' For M2 parts bptr/@bptr can access > address 255''
'' User RAM ( $50-$7F, $C0-$FF ) ''
" M2 parts can access 0 to 511 "
Is there 2 different banks for RAM ( Bank 0 & 1), or just one? For 08m2, PE displays a continuous section of free user RAM (0-127) but in reality these RAM addresses are just a representation of fragmented free sections put together from bigger RAM(S)? So i can't access SFR's with bptr and there is no danger of messing up these registers right?
So if i want to write 0xFF in ram 127 with bptr, i would say:
bptr = 127
@bptr = 0xFF
The same command with poke in relation to the mega map document would be what?
Where is free user RAM address 127 that PE will use in that map?
What about variable b27, where is it's RAM address?
Why it is written '' M2 parts can access 0 to 511 '' when the RAM map show 0-255 ?
The 14m2 has 512 byte of RAM, where is it in this map? Ther are two RAM of 0-255?
Is there an extra Picaxe manual or document on SFRs besides this mega map?
Something that would show individual memory map instead of one collective.
Picaxe is so cool and clear when making code but this makes me feel like hitting my head with a Nerf bat because i really don't get this!
Thanks in advance for help
André
from Montreal
The info does not pop out clearly. I have used bptr, poke, peek and understand these commands. Normally i experiment and research a lot before asking help but there are warnings not to mess with SFR's and risk frying Picaxes so i need some guidance and forum wisdom please!
Here is what i don't understand:
For example, in PE, the 08m2 has user ram 0-127, including variables b0-b27. The map Ver9a.pdf shows something different from 0 to 255 with SFR sections, comments like:
'' For M2 parts bptr/@bptr can access > address 255''
'' User RAM ( $50-$7F, $C0-$FF ) ''
" M2 parts can access 0 to 511 "
Is there 2 different banks for RAM ( Bank 0 & 1), or just one? For 08m2, PE displays a continuous section of free user RAM (0-127) but in reality these RAM addresses are just a representation of fragmented free sections put together from bigger RAM(S)? So i can't access SFR's with bptr and there is no danger of messing up these registers right?
So if i want to write 0xFF in ram 127 with bptr, i would say:
bptr = 127
@bptr = 0xFF
The same command with poke in relation to the mega map document would be what?
Where is free user RAM address 127 that PE will use in that map?
What about variable b27, where is it's RAM address?
Why it is written '' M2 parts can access 0 to 511 '' when the RAM map show 0-255 ?
The 14m2 has 512 byte of RAM, where is it in this map? Ther are two RAM of 0-255?
Is there an extra Picaxe manual or document on SFRs besides this mega map?
Something that would show individual memory map instead of one collective.
Picaxe is so cool and clear when making code but this makes me feel like hitting my head with a Nerf bat because i really don't get this!
Thanks in advance for help
André
from Montreal