What does "As" stand for in this MSP430 opcode table?
I looked all over the place and did not find anything on the meaning of the abbreviation
https://www.ti.com/sc/docs/products/micro/msp430/userguid/as_5.pdf table 5.1 explains that As is
The bits representing the addressing mode used for the source
There is also Ad for the destination, and a whole number of other definitions which you should probably read if you try to understand the documentation.