RSWD

From Intellivision Wiki
Jump to: navigation, search
Instruction NameReturn Status Word
MnemonicRSWD
CP1610 Clock Cycles6
InterruptibleYes
Opcode Range$0038-$003F

The Return Status Word (RSWD) instruction sets or clears the Sign Flag, Zero Flag, Overflow Flag, and Carry Flag according to the value in the specified register. The opcode format is as follows.

   0000:0000:0011:1rrr
where: rrr indicates the target register such that: rrr == 000 indicates register R0 rrr == 001 indicates register R1 rrr == 010 indicates register R2 rrr == 011 indicates register R3 rrr == 100 indicates register R4 rrr == 101 indicates register R5 rrr == 110 indicates register R6 rrr == 111 indicates register R7

After the RSWD instruction is executed, the S, Z, O, and C flags will be set or clear based on the bits in the specified register according to the format below.

   0000:0000:szoc:0000
where: s if one(1), the Sign Flag is set; otherwise, cleared z if one(1), the Zero Flag is set; otherwise, cleared o if one(1), the Overflow Flag is set; otherwise, cleared c if one(1), the Carry Flag is set; otherwise, cleared