DAA (SPC700): Difference between revisions

Revision as of 08:17, 4 July 2024


Basic Info
Addressing Mode	Opcode	Length	Speed
Accumulator	DF	1 byte	3 cycles


Flags Affected
N	V	P	B	H	I	Z	C
	.	.	.	.	.

DAA (Decimal Adjust for Addition) is an SPC700 instruction that performs the following:

If either the carry flag is set or the accumulator exceeds 0x99, add 0x60 to the accumulator and set the carry flag.
Then, if either the half-carry flag is set, or the lower nibble of the accumulator exceeds 0x09, add 0x06 to the accumulator.

Official Super Nintendo development manual on DAA: Table C-14 in Appendix C-8 of Book I
page 3-8-2 of Book I lbid
ares source code, SPC700::instructionDecimalAdjustAdd

@@ Line 37: / Line 37: @@
 '''DAA''' (Decimal Adjust for Addition) is an [[SPC700]] instruction that performs the following:
-# If either the [[carry flag]] is set or the [[accumulator]] exceeds 0x99, 0x60 is added to the accumulator and the carry flag is set.
+# If either the [[carry flag]] is set or the [[accumulator]] exceeds 0x99, add 0x60 to the accumulator and set the carry flag.
-# Then, if either the [[half-carry flag]] is set, or the lower nibble of the accumulator exceeds 0x09, 0x06 is added to the accumulator.
+# Then, if either the [[half-carry flag]] is set, or the lower nibble of the accumulator exceeds 0x09, add 0x06 to the accumulator.
 === See Also ===