OR1 (SPC700): Difference between revisions

Revision as of 17:25, 24 July 2023


Basic Info
Addressing Mode	Opcode	Length	Speed
13-bit Absolute	0A	3 bytes	5 cycles
13-bit Absolute	2A	3 bytes	5 cycles


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

OR1 is an SPC700 instruction that performs a logical or between a memory bit and the carry flag, then stores the disjunction in the carry flag. The low 13 bits of the operand byte specify an absolute address. The high 3 bits of the operand byte specify which bit at that absolute address.

The operands are stored in the instruction stream in the opposite order they appear in the assembler source. In the assembler source, the operand on the right is the source and the operand on the left is the destination.

External Links

Official Super Nintendo development manual on OR1: Appendix C-9 of Book I

@@ Line 40: / Line 40: @@
 |}
-'''OR1''' is an [[SPC700]] instruction that performs a logical or between a memory bit and the [[carry flag]], then stores the disjunction in the carry flag.  The low 13 bits of the operand specify an absolute address.  The high 3 bits of the operand specify which bit at that absolute address.
+'''OR1''' is an [[SPC700]] instruction that performs a logical or between a memory bit and the [[carry flag]], then stores the disjunction in the carry flag.  The low 13 bits of the operand byte specify an absolute address.  The high 3 bits of the operand byte specify which bit at that absolute address.
+The operands are stored in the instruction stream in the opposite order they appear in the assembler source. In the assembler source, the operand on the right is the source and the operand on the left is the destination.
 === See Also ===