We've just updated MediaWiki and its underlying software. If anything doesn't look or work quite right, please mention it to us. --RanAS
Y Index Register
From SnesLab
The Y Index Register on 65x processors often holds the current index when iterating over things. It can be incremented or decremented by one with INY or DEY, but there is no instruction to add or subtract more than one.
On the S-SMP it is always 8 bits wide. On the 65c816, it may be 8 or 16 bits wide.
Unlike the X index register, there are no instructions to transfer value of the stack pointer to/from Y.
It is not specified to have any particular value after reset.
See Also
Reference
- 8.1.3 of page 3-8-4 of Book I of the official Super Nintendo development manual