TEA encryption and embedding in PBP

Hey,

im interested in implemeting the TEA encription algorithm into a pic, but im confused on how to do it. Looking at the test file that comes with TEA in assembler:

include "p16f84.inc"

include "math32.inc"

cblock 0x0c ;Dummy block to set the start of usable memory
endc


org 0 ;Code start

test mmovl32 vy, 0x00000000 ;Set the plaintext
mmovl32 vz, 0x00000000

mmovl32 ka, 0x00000000 ;Set the key
mmovl32 kb, 0x00000000
mmovl32 kc, 0x00000000
mmovl32 kd, 0x00000000

call TEAenc ;Encipher...
call TEAdec ;...and decipher.
goto test ;Once again!


include "tea.asm" ;Include the TEA routines


end

this all looks ok, but the question is can i direcly access the vy and vz registers from PBP or do i have to define them somehow?

also i saw this post on practically the same subject,
http://www.picbasic.co.uk/forum/show...ight=assembler
but i dont quite know what the conclusions were.

there was another idea on how to encrypt the information in the reply (to long to post), but i dont really understand it. could someone explain?