This page describes the following instruction:
- Group: PAIR
- Mnemonic: ra
- Opcode: 201d, C9h
- Encoding: 1_100_1001b (PAIR_SRC_DST)
- Pseudo-code: if (o+r)>255 then d+=1
- R:RESULT A:ADD
- Source is the R register.
- Add source to O. If this produces a carry bit, add the carry bit to D.
The 'A' destination takes the source value as the addend which is added to the Data pointer (register pair D:O). See In-Page Branching for more on this.