BRK (SPC700): Difference between revisions

Latest revision as of 00:31, 14 August 2024


Basic Info
Addressing Mode	Opcode	Length	Speed
Stack / Interrupt	0F	1 byte	8 cycles


Flags Affected
N	V	P	B	H	I	Z	C
.	.	.	1	.	0	.	.

BRK is an SPC700 instruction that triggers a software interrupt. The program counter and flags are pushed to the stack. The program counter then jumps to the address stored at $FFDE.

Syntax

BRK

BRK very well could be the only interrupt source on the S-SMP. It is the only instruction to unconditionally set the break flag.

According to fullsnes, EI and DI have no effect other than toggling the interrupt enable flag, so the SPC700's BRK seems to be non-maskable like the 65c816's BRK.

To return from the interrupt handler, use RETI.

References

Table C-16 in Appendix C-9 of Book I of the official Super Nintendo development manual
anomie's SPC700 doc

@@ Line 44: / Line 44: @@
 BRK very well could be the only interrupt source on the S-SMP.  It is the only instruction to unconditionally set the [[break flag]].
-To return from the interrupt, use [[RETI]].
+According to [[fullsnes]], [[EI]] and [[DI]] have no effect other than toggling the [[interrupt enable flag]], so the SPC700's BRK seems to be non-maskable like the 65c816's [[BRK]].
+To return from the [[interrupt handler]], use [[RETI]].
 === See Also ===
@@ Line 50: / Line 52: @@
 * [[SLEEP]]
 * [[STOP]]
-* [[EI]]
-* [[DI]]
 === References ===