Porting Propeller 1 code to Propeller 2

• Notes on converting code from Spin1 to Spin2
  • Setting clock is different: 
    • Instead of 
    • Do this:
  • All functions (PUB and PRI) now require parenthesis, even if doesn't have parameters
    • Instead of "PUB main" use "PUB main()"
  • All functions that return a value must declare the return value
    • Instead of "PUB GetByte" do "PUB GetByte():r" where "r" is the value to be returned.
  •  Use "jm_fullduplexserial.spin2" instead of "fullduplexserial.spin"
    • Note that there may be an issue with function name "fdec", just rename it to "fdec2" or something as "fdec" has become a reserved word.
    • Can use "ser.tstart(baud)" where baud might be 115200 to use usual pins and settings
    • There are some slight differences/improvements in this P2 version
  • The way to drive pins has changed a bit
    • P1 way was like:  to set a pin low.  You can still do it that way and there is even a OUTB and DIRB and INB now.  But, syntax is now OUTA.[PinResetn]~~.  Note you have to add the "." to get it to work.
    • But, new way is with commands like:      where the pin number argument can range from 0 to 63. 
      • There is also pinh, pinf, pinr, etc.
      • You can also use "addpins" to affect multiple sequential pins at once.
  • The way to do delays based on clock ticks has changed
    • The old way:  doesn't work
    • An easy way now is to use waitms(500) to do same thing with P2  

• The below posted to tricks & traps forum discussion here.

• Common substitutions that need to be made in PASM2:  
  • PAR --> PTRA
  • MINS --> FGES
  • MAXS --> FLES
  • MOVS --> SETS 
  • ":" --> "." (sometimes in many places, the local variable indicator has changed.)
  • SETD --> SETD2  (SETD is an instruction in P2)
  •  cmps wc,wr --> subs wc
  • command := cmd << 16 + argptr --> command := cmd << 24 + argptr  (pointer space is now larger than 16 bits, but can still use upper 8 bits for something else)
  • Using QROTATE to fix missing sin table
  •  Used MUL to speed multiply
  • SUB with wz,nr cannot be used as there is no "NR" now.  Use CMP instead.  
  • waitcnt x,#0 --> waitx x
  • The usual wait sequence:  
    • mov t7,cnt
      add t7,delaycnt2
      waitcnt t7,#0
    • Is Now:
    •  getct t7
      addct1 t7,delaycnt2
      waitct1

• New way to do byte jump table (search link in top line)

• Note that self-generating code must be kept in cog and not used in hubexec mode

• For Spin code:
  • All function must use "()" parenthesis in definition and call
  • Return values need to be declared explicitely.  Can usually just add a ":r".   

• You only need to set _clkfreq now, no crystal setting needed.

• There is a Port B in P2 now, so...
  • You might need to change INA/OUTA/DIRA to match your actual setup
  • Be careful if there's any INA/OUTB/DIRB usage in your spin1 code, you may need to change that